';
			//print_r($data);
			//echo '
';
	
			// displaying the table: headers
			echo '';
			echo '	';
			echo '		';
			echo '		';
			echo '		';
			echo '		';
			echo '	';
	
	
			// displaying the table: the content
			foreach ($options as $key=>$value)
			{
				$absolute_number = $data[$value['question_option_id']]['total'];
				if($number_of_answers == 0)
				{
					$answers_number = 0;
				}
				else
				{
					$answers_number = $absolute_number/$number_of_answers*100;
				}
				echo '	';
				echo '		';
				echo '		';
				echo '		';
				echo '		';
				echo '	';
			}
	
			// displaying the table: footer (totals)
			echo '	';
			echo '		';
			echo '		';
			echo '		';
			echo '		';
			echo '	';
	
			echo '
 
'.get_lang('AbsoluteTotal').'
'.get_lang('Percentage').'
'.get_lang('VisualRepresentation').'
'.$value['option_text'].'
'.$absolute_number.'
'.round($answers_number, 2).' %
';
				$size = $answers_number*2;
				if ($size > 0)
				{
					echo '
 
';
				}
				echo '		
'.get_lang('Total').'
'.($number_of_answers==0?'0':$number_of_answers).'
 
 
';
		}
	
		if (isset($_GET['viewoption']))
		{
			echo get_lang('PeopleWhoAnswered').': '.$options[$_GET['viewoption']]['option_text'].'
';
	
			if (is_numeric($_GET['value']))
			{
				$sql_restriction = "AND value='".Database::escape_string($_GET['value'])."'";
			}
	
			$sql = "SELECT user FROM $table_survey_answer WHERE option_id = '".Database::escape_string($_GET['viewoption'])."' $sql_restriction";
			$result = api_sql_query($sql, __FILE__, __LINE__);
			while ($row = Database::fetch_array($result))
			{
				echo ''.$row['user'].'
';
			}
		}
	}
	/**
	 * Display score data about a survey question
	 * @param	array	Question info
	 * @param	integer	The offset of results shown
	 * @return	void 	(direct output)
	 */
	function display_question_report_score($survey_data, $question, $offset)
	{
		// Database table definitions
		$table_survey_question 			= Database :: get_course_table(TABLE_SURVEY_QUESTION);
		$table_survey_question_option 	= Database :: get_course_table(TABLE_SURVEY_QUESTION_OPTION);
		$table_survey_answer 			= Database :: get_course_table(TABLE_SURVEY_ANSWER);
	
		// getting the options
		$sql = "SELECT * FROM $table_survey_question_option
					WHERE survey_id='".Database::escape_string($_GET['survey_id'])."'
					AND question_id = '".Database::escape_string($question['question_id'])."'
					ORDER BY sort ASC";
		$result = api_sql_query($sql, __FILE__, __LINE__);
		while ($row = Database::fetch_array($result))
		{
			$options[$row['question_option_id']] = $row;
		}
	
		// getting the answers
		$sql = "SELECT *, count(answer_id) as total FROM $table_survey_answer
					WHERE survey_id='".Database::escape_string($_GET['survey_id'])."'
					AND question_id = '".Database::escape_string($question['question_id'])."'
					GROUP BY option_id, value";
		$result = api_sql_query($sql, __FILE__, __LINE__);
		while ($row = Database::fetch_array($result))
		{
			$number_of_answers += $row['total'];
			$data[$row['option_id']][$row['value']] = $row;
		}
		// displaying the table: headers
		echo '';
		echo '	';
		echo '		';
		echo '		';
		echo '		';
		echo '		';
		echo '		';
		echo '	';
		// displaying the table: the content
		foreach ($options as $key=>$value)
		{
			for ($i=1; $i<=$question['max_value']; $i++)
			{
				$absolute_number = $data[$value['question_option_id']][$i]['total'];
	
				echo '	';
				echo '		';
				echo '		';
				echo '		';
				echo '		';
				echo '		';
				echo '	';
			}
		}
			// displaying the table: footer (totals)
			echo '	';
			echo '		';
			echo '		';
			echo '		';
			echo '		';
			echo '		';
			echo '	';
	
			echo '
 
'.get_lang('Score').'
'.get_lang('AbsoluteTotal').'
'.get_lang('Percentage').'
'.get_lang('VisualRepresentation').'
'.$value['option_text'].'
'.$i.'
'.$absolute_number.'
'.round($absolute_number/$number_of_answers*100, 2).' %
';
				$size = ($absolute_number/$number_of_answers*100*2);
				if ($size > 0)
				{
					echo '			
 
';
				}
				echo '		
'.get_lang('Total').'
 
'.$number_of_answers.'
 
 
';
	}
	
	/**
	 * This functions displays the complete reporting
	 * @return	string	HTML code
	 * @todo open questions are not in the complete report yet.
	 * @author Patrick Cool , Ghent University
	 * @version February 2007
	 */
	function display_complete_report()
	{
		// Database table definitions
		$table_survey_question 			= Database :: get_course_table(TABLE_SURVEY_QUESTION);
		$table_survey_question_option 	= Database :: get_course_table(TABLE_SURVEY_QUESTION_OPTION);
		$table_survey_answer 			= Database :: get_course_table(TABLE_SURVEY_ANSWER);
	
		// the form
		echo '';
		echo '';
		echo '';
		echo '';
		echo '
';
		echo '';
		echo '';
		echo '
';
		echo '
';
		echo ' '.get_lang('ExportAsCSV').'';
		echo ' '.get_lang('ExportAsXLS').'';
		// the table
		echo '
';
		// getting the number of options per question
		echo '	';
		echo '		';
		
		$display_extra_user_fields = false;
		if (!($_POST['submit_question_filter'] OR $_POST['export_report']) OR !empty($_POST['fields_filter']))
		{
			//show user fields section with a big th colspan that spans over all fields
			$extra_user_fields = UserManager::get_extra_fields(0,0,5,'ASC',false);
			$num = count($extra_user_fields);
			echo '';		
			$display_extra_user_fields = true;
		}

		$sql = "SELECT questions.question_id, questions.type, questions.survey_question, count(options.question_option_id) as number_of_options
				FROM $table_survey_question questions LEFT JOIN $table_survey_question_option options
				ON questions.question_id = options.question_id
				WHERE questions.question_id = options.question_id
				AND questions.survey_id = '".Database::escape_string($_GET['survey_id'])."'
				GROUP BY questions.question_id";
		$result = api_sql_query($sql, __FILE__, __LINE__);
		while ($row = Database::fetch_array($result))
		{
			// we show the questions if
			// 1. there is no question filter and the export button has not been clicked
			// 2. there is a quesiton filter but the question is selected for display
			if (!($_POST['submit_question_filter']  OR $_POST['export_report']) OR in_array($row['question_id'], $_POST['questions_filter']))
			{
				// we do not show comment and pagebreak question types
				if ($row['type'] <> 'comment' AND $row['type'] <> 'pagebreak')
				{
					echo '		0)
					{
						echo ' colspan="'.$row['number_of_options'].'"';
					}
					echo '>';
	
					echo ' ';
					echo $row['survey_question'];
					echo '';
					echo '';
				}
			}
			$questions[$row['question_id']] = $row;
		}
		echo '	';
		// getting all the questions and options
		echo '	';
		echo '		'; // the user column
		
		if (!($_POST['submit_question_filter'] OR $_POST['export_report']) OR !empty($_POST['fields_filter']))
		{
			//show the fields names for user fields
			foreach($extra_user_fields as $field)
			{
				echo '';
			}
		}
		
		$sql = "SELECT 	survey_question.question_id, survey_question.survey_id, survey_question.survey_question, survey_question.display, survey_question.sort, survey_question.type,
						survey_question_option.question_option_id, survey_question_option.option_text, survey_question_option.sort as option_sort
				FROM $table_survey_question survey_question
				LEFT JOIN $table_survey_question_option survey_question_option
				ON survey_question.question_id = survey_question_option.question_id
				WHERE survey_question.survey_id = '".Database::escape_string($_GET['survey_id'])."'
				ORDER BY survey_question.sort ASC";
		$result = api_sql_query($sql, __FILE__, __LINE__);
		while ($row = Database::fetch_array($result))
		{
			// we show the options if
			// 1. there is no question filter and the export button has not been clicked
			// 2. there is a quesiton filter but the question is selected for display
			if (!($_POST['submit_question_filter'] OR $_POST['export_report']) OR in_array($row['question_id'], $_POST['questions_filter']))
			{
				// we do not show comment and pagebreak question types
				if ($row['type'] <> 'comment' AND $row['type'] <> 'pagebreak')
				{
					echo '			';
					$possible_answers[$row['question_id']][$row['question_option_id']] =$row['question_option_id'];
				}
			}
		}
		echo '	';
	
		// getting all the answers of the users
		$old_user='';
		$answers_of_user = array();
		$sql = "SELECT * FROM $table_survey_answer WHERE survey_id='".Database::escape_string($_GET['survey_id'])."' ORDER BY user ASC";
		$result = api_sql_query($sql, __FILE__, __LINE__);
		while ($row = Database::fetch_array($result))
		{
			if ($old_user <> $row['user'] AND $old_user<>'')
			{
				SurveyUtil::display_complete_report_row($possible_answers, $answers_of_user, $old_user, $questions, $display_extra_user_fields);
				$answers_of_user=array();
			}
			if ($questions[$row['question_id']]['type']<> 'open')
			{
				$answers_of_user[$row['question_id']][$row['option_id']] = $row;
			}
			else 
			{
				$answers_of_user[$row['question_id']][0] = $row;
			}
			$old_user = $row['user'];
		}
		SurveyUtil::display_complete_report_row($possible_answers, $answers_of_user, $old_user, $questions, $display_extra_user_fields); // this is to display the last user
	
		echo '
';
		if ($_POST['submit_question_filter'] OR $_POST['export_report'])
		{
			echo '			';
		}
		echo '			';
		echo '
0?' colspan="'.$num.'"':'').'>';
			echo ' ';
			echo get_lang('UserFields');
			echo '';
			echo '
 
'.$field[3].'
';
					echo $row['option_text'];
					echo '
';
	
		echo '
';
	}
	
	
	/**
	 * This function displays a row (= a user and his/her answers) in the table of the complete report.
	 *
	 * @param 	array	Possible options
	 * @param 	array 	User answers
	 * @param	mixed	User ID or user details string
	 * @param	boolean	Whether to show extra user fields or not
	 * @author Patrick Cool , Ghent University
	 * @version February 2007 - Updated March 2008
	 */
	function display_complete_report_row($possible_options, $answers_of_user, $user, $questions, $display_extra_user_fields=false)
	{
		global $survey_data;
		
		$table_survey_question = Database :: get_course_table(TABLE_SURVEY_QUESTION);
		echo '';
		if ($survey_data['anonymous'] == 0)
		{
			if(intval($user)!==0)
			{
				$sql = 'SELECT firstname, lastname FROM '.Database::get_main_table(TABLE_MAIN_USER).' WHERE user_id='.intval($user);
				$rs = api_sql_query($sql, __FILE__, __LINE__);
				if($row = Database::fetch_array($rs))
				{
					$user_displayed = $row['lastname'].' '.$row['firstname'];
				}
				else
				{
					$user_displayed = '-';
				}
				echo '		'.$user_displayed.''; // the user column
			}
			else
			{
				echo '		'.$user.''; // the user column
			}
		}
		else
		{ 
			echo '-';
		}
		
		if ($display_extra_user_fields)
		{
			//show user fields data, if any, for this user
			$user_fields_values = UserManager::get_extra_user_data(intval($user),false,false);
			foreach($user_fields_values as $value)
			{
				echo ''.$value.'';
			}
		}
	
		foreach ($possible_options as $question_id=>$possible_option)
		{
			if ($questions[$question_id]['type'] == 'open')
			{
				echo '';
				echo $answers_of_user[$question_id]['0']['option_id'];
				echo '';
			}
			else 
			{		
				foreach ($possible_option as $option_id=>$value)
				{
					echo '';
					if (!empty($answers_of_user[$question_id][$option_id]))
					{
						if ($answers_of_user[$question_id][$option_id]['value']<>0)
						{
							echo $answers_of_user[$question_id][$option_id]['value'];
						}
						else
						{
							echo 'v';
						}
					}
				}
			}
			
		}
		echo '';
	}
	
	
	/**
	 * Quite similar to display_complete_report(), returns an HTML string 
	 * that can be used in a csv file
	 * @todo consider merging this function with display_complete_report
	 * @return	string	The contents of a csv file
	 * @author Patrick Cool , Ghent University
	 * @version February 2007
	 */
	function export_complete_report()
	{
		// Database table definitions
		$table_survey_question 			= Database :: get_course_table(TABLE_SURVEY_QUESTION);
		$table_survey_question_option 	= Database :: get_course_table(TABLE_SURVEY_QUESTION_OPTION);
		$table_survey_answer 			= Database :: get_course_table(TABLE_SURVEY_ANSWER);
	
		// the first column
		$return = ';';
	
		//show extra fields blank space (enough for extra fields on next line)
		$display_extra_user_fields = false;
		if (!($_POST['submit_question_filter'] OR $_POST['export_report']) OR !empty($_POST['fields_filter']))
		{
			//show user fields section with a big th colspan that spans over all fields
			$extra_user_fields = UserManager::get_extra_fields(0,0,5,'ASC',false);
			$num = count($extra_user_fields);
			$return .= str_repeat(';',$num);
			$display_extra_user_fields = true;
		}
		
	
		$sql = "SELECT questions.question_id, questions.type, questions.survey_question, count(options.question_option_id) as number_of_options
				FROM $table_survey_question questions LEFT JOIN $table_survey_question_option options
				ON questions.question_id = options.question_id "
				." AND questions.survey_id = '".Database::escape_string($_GET['survey_id'])."'
				GROUP BY questions.question_id";
		$result = api_sql_query($sql, __FILE__, __LINE__);
		while ($row = Database::fetch_array($result))
		{
			// we show the questions if
			// 1. there is no question filter and the export button has not been clicked
			// 2. there is a quesiton filter but the question is selected for display
			if (!($_POST['submit_question_filter']) OR (is_array($_POST['questions_filter']) && in_array($row['question_id'], $_POST['questions_filter'])))
			{
				// we do not show comment and pagebreak question types
				if ($row['type'] <> 'comment' AND $row['type'] <> 'pagebreak')
				{
					if($row['number_of_options'] == 0 && $row['type']=='open')
					{
							$return .= str_replace("\r\n",'  ',html_entity_decode(strip_tags($row['survey_question']))).';';					
					}
					else
					{
						for ($ii = 0; $ii < $row['number_of_options']; $ii ++)
						{
							$return .= str_replace("\r\n",'  ',html_entity_decode(strip_tags($row['survey_question']))).';';
						}
					}
				}
			}
		}
		$return .= "\n";
	
		// getting all the questions and options
		$return .= ';';
		
		//show extra field values
		if (!($_POST['submit_question_filter'] OR $_POST['export_report']) OR !empty($_POST['fields_filter']))
		{
			//show the fields names for user fields
			foreach($extra_user_fields as $field)
			{
				$return .= '"'.str_replace("\r\n",'  ',html_entity_decode(strip_tags($field[3]))).'";';
			}
		}
		
		$sql = "SELECT 	survey_question.question_id, survey_question.survey_id, survey_question.survey_question, survey_question.display, survey_question.sort, survey_question.type,
						survey_question_option.question_option_id, survey_question_option.option_text, survey_question_option.sort as option_sort
				FROM $table_survey_question survey_question
				LEFT JOIN $table_survey_question_option survey_question_option
				ON survey_question.question_id = survey_question_option.question_id
				WHERE survey_question.survey_id = '".Database::escape_string($_GET['survey_id'])."'
				ORDER BY survey_question.sort ASC";
		$result = api_sql_query($sql, __FILE__, __LINE__);
		$possible_answers = array();
		$possible_answers_type = array();
		while ($row = Database::fetch_array($result))
		{
			// we show the options if
			// 1. there is no question filter and the export button has not been clicked
			// 2. there is a quesiton filter but the question is selected for display
			if (!($_POST['submit_question_filter']) OR (is_array($_POST['questions_filter']) && in_array($row['question_id'], $_POST['questions_filter'])))
			{
				// we do not show comment and pagebreak question types
				if ($row['type'] <> 'comment' AND $row['type'] <> 'pagebreak')
				{
					$return .= html_entity_decode(strip_tags($row['option_text'])).';';
					$possible_answers[$row['question_id']][$row['question_option_id']] =$row['question_option_id'];
					$possible_answers_type[$row['question_id']] = $row['type'];
				}
			}
		}
		$return .= "\n";
	
		// getting all the answers of the users
		$old_user='';
		$answers_of_user = array();
		$sql = "SELECT * FROM $table_survey_answer WHERE survey_id='".Database::escape_string($_GET['survey_id'])."' ORDER BY user ASC";
		
		$open_question_iterator = 1;
		$result = api_sql_query($sql, __FILE__, __LINE__);
		while ($row = Database::fetch_array($result))
		{
			if ($old_user <> $row['user'] AND $old_user <> '')
			{
				$return .= SurveyUtil::export_complete_report_row($possible_answers, $answers_of_user, $old_user, $display_extra_user_fields);
				$answers_of_user=array();
			}
			if($possible_answers_type[$row['question_id']] == 'open')
			{
				$temp_id = 'open'.$open_question_iterator;
				$answers_of_user[$row['question_id']][$temp_id] = $row;
				$open_question_iterator++;
			}
			else
			{
				$answers_of_user[$row['question_id']][$row['option_id']] = $row;
			}
			$old_user = $row['user'];
		}
		$return .= SurveyUtil::export_complete_report_row($possible_answers, $answers_of_user, $old_user, $display_extra_user_fields); // this is to display the last user
		return $return;
	}
	
	
	/**
	 * Add a line to the csv file
	 *
	 * @param	array	Possible answers
	 * @param	array	User's answers
	 * @param 	mixed	User ID or user details as string - Used as a string in the result string
	 * @param	boolean	Whether to display user fields or not
	 * @return	string	One line of the csv file
	 * @author Patrick Cool , Ghent University
	 * @version February 2007
	 */
	function export_complete_report_row($possible_options, $answers_of_user, $user, $display_extra_user_fields=false)
	{
		$return = $user.';'; // the user column

		if($display_extra_user_fields)
		{
			//show user fields data, if any, for this user
			$user_fields_values = UserManager::get_extra_user_data(intval($user),false,false);
			foreach($user_fields_values as $value)
			{
				$return .= '"'.str_replace('"','""',html_entity_decode(strip_tags($value))).'";';
			}
		}
	
	
		if(is_array($possible_options))
		{
			foreach ($possible_options as $question_id=>$possible_option)
			{
				if(is_array($possible_option) && count($possible_option)>0)
				{
					foreach ($possible_option as $option_id=>$value)
					{
						$key = array_keys($answers_of_user[$question_id]);
						if(substr($key[0],0,4)=='open')
						{
							$return .= '"'.str_replace('"','""',html_entity_decode(strip_tags($answers_of_user[$question_id][$key[0]]['option_id']))).'"';
						}
						elseif (!empty($answers_of_user[$question_id][$option_id]))
						{
							$return .= 'v';
						}
						$return .= ';';
					}
				}
			}
		}
		$return .= "\n";
		return $return;
	}
	/**
	 * Quite similar to display_complete_report(), returns an HTML string 
	 * that can be used in a csv file
	 * @todo consider merging this function with display_complete_report
	 * @return	string	The contents of a csv file
	 * @author Patrick Cool , Ghent University
	 * @version February 2007
	 */
	function export_complete_report_xls($filename)
	{
		require_once(api_get_path(LIBRARY_PATH).'pear/Spreadsheet_Excel_Writer/Writer.php');
		$workbook = new Spreadsheet_Excel_Writer();
		$workbook->send($filename);
		$worksheet =& $workbook->addWorksheet('Report 1');
		$line = 0;
		$column = 1; //skip the first column (row titles)

		//show extra fields blank space (enough for extra fields on next line)
		$display_extra_user_fields = false;
		if (!($_POST['submit_question_filter'] OR $_POST['export_report']) OR !empty($_POST['fields_filter']))
		{
			//show user fields section with a big th colspan that spans over all fields
			$extra_user_fields = UserManager::get_extra_fields(0,0,5,'ASC',false);
			$num = count($extra_user_fields);
			for($i=0;$i<$num;$i++)
			{
				$worksheet->write($line,$column,'');
				$column ++;
			}
			$display_extra_user_fields = true;
		}
		
		// Database table definitions
		$table_survey_question 			= Database :: get_course_table(TABLE_SURVEY_QUESTION);
		$table_survey_question_option 	= Database :: get_course_table(TABLE_SURVEY_QUESTION_OPTION);
		$table_survey_answer 			= Database :: get_course_table(TABLE_SURVEY_ANSWER);
	
		// First line (questions)
		$sql = "SELECT questions.question_id, questions.type, questions.survey_question, count(options.question_option_id) as number_of_options
				FROM $table_survey_question questions LEFT JOIN $table_survey_question_option options
				ON questions.question_id = options.question_id "
				." AND questions.survey_id = '".Database::escape_string($_GET['survey_id'])."'
				GROUP BY questions.question_id";
		$result = api_sql_query($sql, __FILE__, __LINE__);
		while ($row = Database::fetch_array($result))
		{
			// we show the questions if
			// 1. there is no question filter and the export button has not been clicked
			// 2. there is a quesiton filter but the question is selected for display
			if (!($_POST['submit_question_filter']) OR (is_array($_POST['questions_filter']) && in_array($row['question_id'], $_POST['questions_filter'])))
			{
				// we do not show comment and pagebreak question types
				if ($row['type'] <> 'comment' AND $row['type'] <> 'pagebreak')
				{
					if($row['number_of_options'] == 0 && $row['type']=='open')
					{
							$worksheet->write($line,$column,html_entity_decode(strip_tags($row['survey_question'])));
							$column ++;					
					}
					else
					{
						for ($ii = 0; $ii < $row['number_of_options']; $ii ++)
						{
							$worksheet->write($line,$column,html_entity_decode(strip_tags($row['survey_question'])));
							$column ++;
						}
					}
				}
			}
		}
		$line++;
		$column = 1;

		//show extra field values
		if ($display_extra_user_fields)
		{
			//show the fields names for user fields
			foreach($extra_user_fields as $field)
			{
				$worksheet->write($line,$column,html_entity_decode(strip_tags($field[3])));
				$column++;
			}
		}
	
		// getting all the questions and options (second line)
		$sql = "SELECT 	survey_question.question_id, survey_question.survey_id, survey_question.survey_question, survey_question.display, survey_question.sort, survey_question.type,
						survey_question_option.question_option_id, survey_question_option.option_text, survey_question_option.sort as option_sort
				FROM $table_survey_question survey_question
				LEFT JOIN $table_survey_question_option survey_question_option
				ON survey_question.question_id = survey_question_option.question_id
				WHERE survey_question.survey_id = '".Database::escape_string($_GET['survey_id'])."'
				ORDER BY survey_question.sort ASC";
		$result = api_sql_query($sql, __FILE__, __LINE__);
		$possible_answers = array();
		$possible_answers_type = array();
		while ($row = Database::fetch_array($result))
		{
			// we show the options if
			// 1. there is no question filter and the export button has not been clicked
			// 2. there is a quesiton filter but the question is selected for display
			if (!($_POST['submit_question_filter']) OR (is_array($_POST['questions_filter']) && in_array($row['question_id'], $_POST['questions_filter'])))
			{
				// we do not show comment and pagebreak question types
				if ($row['type'] <> 'comment' AND $row['type'] <> 'pagebreak')
				{
					$worksheet->write($line,$column,html_entity_decode(strip_tags($row['option_text'])));
					$possible_answers[$row['question_id']][$row['question_option_id']] =$row['question_option_id'];
					$possible_answers_type[$row['question_id']] = $row['type'];
					$column++;
				}
			}
		}

		// getting all the answers of the users
		$line ++;
		$column = 0;
		$old_user='';
		$answers_of_user = array();
		$sql = "SELECT * FROM $table_survey_answer " .
				"WHERE survey_id='".Database::escape_string($_GET['survey_id'])."' " .
						"ORDER BY user ASC";
		$open_question_iterator = 1;
		$result = api_sql_query($sql, __FILE__, __LINE__);
		while ($row = Database::fetch_array($result))
		{
			if ($old_user <> $row['user'] AND $old_user <> '')
			{
				$return = SurveyUtil::export_complete_report_row_xls($possible_answers, $answers_of_user, $old_user, $display_extra_user_fields);
				foreach($return as $elem)
				{
					$worsheet->write($line,$column,$elem);
					$column++;
				}
				$answers_of_user=array();
				$line++;
				$column=0;
			}
			if($possible_answers_type[$row['question_id']] == 'open')
			{
				$temp_id = 'open'.$open_question_iterator;
				$answers_of_user[$row['question_id']][$temp_id] = $row;
				$open_question_iterator++;
			}
			else
			{
				$answers_of_user[$row['question_id']][$row['option_id']] = $row;
			}
			$old_user = $row['user'];
		}
		$return = SurveyUtil::export_complete_report_row_xls($possible_answers, $answers_of_user, $old_user); // this is to display the last user
		foreach($return as $elem)
		{
			$worksheet->write($line,$column,$elem);
			$column++;
		}
		$workbook->close();
		return null;
	}
	
	
	/**
	 * Add a line to the csv file
	 *
	 * @param	array	Possible answers
	 * @param	array	User's answers
	 * @param 	mixed	User ID or user details as string - Used as a string in the result string
	 * @param	boolean	Whether to display user fields or not
	 * @return	string	One line of the csv file
	 */
	function export_complete_report_row_xls($possible_options, $answers_of_user, $user, $display_extra_user_fields=false)
	{
		$return = array();
		$return[] = $user; // the user column
	
		if($display_extra_user_fields)
		{
			//show user fields data, if any, for this user
			$user_fields_values = UserManager::get_extra_user_data(intval($user),false,false);
			foreach($user_fields_values as $value)
			{
				$return[] = html_entity_decode(strip_tags($value));
			}
		}

		if(is_array($possible_options))
		{
			foreach ($possible_options as $question_id=>$possible_option)
			{
				if(is_array($possible_option) && count($possible_option)>0)
				{
					foreach ($possible_option as $option_id=>$value)
					{
						$key = array_keys($answers_of_user[$question_id]);
						if(substr($key[0],0,4)=='open')
						{
							$return[] = html_entity_decode(strip_tags($answers_of_user[$question_id][$key[0]]['option_id']));
						}
						elseif (!empty($answers_of_user[$question_id][$option_id]))
						{
							$return[] = 'v';
						}
						else
						{
							$return[] = '';
						}
					}
				}
			}
		}
		return $return;
	}
	
	/**
	 * This function displays the comparative report which allows you to compare two questions
	 * A comparative report creates a table where one question is on the x axis and a second question is on the y axis.
	 * In the intersection is the number of people who have answerd positive on both options.
	 *
	 * @return	string	HTML code
	 *
	 * @author Patrick Cool , Ghent University
	 * @version February 2007
	 */
	function display_comparative_report()
	{
		// allowed question types for comparative report
		$allowed_question_types = array('yesno', 'multiplechoice', 'multipleresponse', 'dropdown', 'percentage', 'score');
	
		// getting all the questions
		$questions = survey_manager::get_questions($_GET['survey_id']);
	
		// displaying an information message that only the questions with predefined answers can be used in a comparative report
		Display::display_normal_message(get_lang('OnlyQuestionsWithPredefinedAnswers'), false);
	
		// The form for selecting the axis of the table
		echo '
';
		// survey_id
		echo '';
		echo '';
		// X axis
		echo get_lang('SelectXAxis').': ';
		echo '';
		echo '---';
		foreach ($questions as $key=>$question)
		{
			if (in_array($question['type'], $allowed_question_types))
			{
				echo ''.substr(strip_tags($question['question']), 0, 50).'';
			}
		}
		echo '

';
		// Y axis
		echo get_lang('SelectYAxis').': ';
		echo '';
		echo '---';
		foreach ($questions as $key=>$question)
		{
			if (in_array($question['type'], $allowed_question_types))
			{
				echo ''.substr(strip_tags($question['question']), 0, 50).'';
			}
		}
		echo '

';
		echo '';
		echo '
';
	
		// getting all the information of the x axis
		if (isset($_GET['xaxis']) AND is_numeric($_GET['xaxis']))
		{
			$question_x = survey_manager::get_question($_GET['xaxis']);
		}
	
		// getting all the information of the y axis
		if (isset($_GET['yaxis']) AND is_numeric($_GET['yaxis']))
		{
			$question_y = survey_manager::get_question($_GET['yaxis']);
		}
	
		if (isset($_GET['xaxis']) AND is_numeric($_GET['xaxis']) AND isset($_GET['yaxis']) AND is_numeric($_GET['yaxis']))
		{
			// getting the answers of the two questions
			$answers_x = SurveyUtil::get_answers_of_question_by_user($_GET['survey_id'], $_GET['xaxis']);
			$answers_y = SurveyUtil::get_answers_of_question_by_user($_GET['survey_id'], $_GET['yaxis']);
	
			// displaying the table
			echo '';
	
			// the header
			echo '	';
			for ($ii=0; $ii<=count($question_x['answers']); $ii++)
			{
				if ($ii == 0)
				{
					echo '		';
				}
				else
				{
					if ($question_x['type']=='score')
					{
						for($x=1; $x<=$question_x['maximum_score']; $x++)
						{
							echo '		';
						}
						$x='';
					}
					else
					{
						echo '		';
					}
				}
			}
			echo '	';
	
			// the main part
			for ($ij=0; $ij';
						for ($ii=0; $ii<=count($question_x['answers']); $ii++)
						{
							if ($question_x['type']=='score')
							{
								for($x=1; $x<=$question_x['maximum_score']; $x++)
								{
									if ($ii == 0)
									{
										echo '		';
										break;
									}
									else
									{
										echo '		';
									}
								}
							}
							else
							{
								if ($ii == 0)
								{
									echo '		';
								}
								else
								{
									echo '		';
								}
							}
						}
						echo '	';
					}
				}
				// The Y axis is NOT a score question type so the number of rows = the number of options
				else
				{
					echo '	';
					for ($ii=0; $ii<=count($question_x['answers']); $ii++)
					{
							if ($question_x['type']=='score')
							{
								for($x=1; $x<=$question_x['maximum_score']; $x++)
								{
									if ($ii == 0)
									{
										echo '		';
										break;
									}
									else
									{
										echo '		';
									}
								}
							}
							else
							{
								if ($ii == 0)
								{
									echo '		';
								}
								else
								{
									echo '		';
								}
							}
					}
					echo '	';
				}
			}
			echo '
 
'.$question_x['answers'][($ii-1)].'
'.$x.'
'.$question_x['answers'][($ii-1)].'
'.$question_y['answers'][($ij)].' '.$y.'
';
										echo SurveyUtil::comparative_check($answers_x, $answers_y, $question_x['answersid'][($ii-1)], $question_y['answersid'][($ij)], $x, $y);
										echo '
'.$question_y['answers'][($ij)].' '.$y.'
';
									echo SurveyUtil::comparative_check($answers_x, $answers_y, $question_x['answersid'][($ii-1)], $question_y['answersid'][($ij)], 0, $y);
									echo '
'.$question_y['answers'][($ij)].'
';
										echo SurveyUtil::comparative_check($answers_x, $answers_y, $question_x['answersid'][($ii-1)], $question_y['answersid'][($ij)], $x, 0);
										echo '
'.$question_y['answers'][($ij)].'
';
									echo SurveyUtil::comparative_check($answers_x, $answers_y, $question_x['answersid'][($ii-1)], $question_y['answersid'][($ij)]);
									echo '
';
		}
	}
	
	/**
	 * Get all the answers of a question grouped by user
	 *
	 * @param	integer	Survey ID
	 * @param	integer	Question ID
	 * @return 	Array	Array containing all answers of all users, grouped by user
	 *
	 * @author Patrick Cool , Ghent University
	 * @version February 2007 - Updated March 2008
	 */
	function get_answers_of_question_by_user($survey_id, $question_id)
	{
		// Database table definitions
		$table_survey_question 			= Database :: get_course_table(TABLE_SURVEY_QUESTION);
		$table_survey_question_option 	= Database :: get_course_table(TABLE_SURVEY_QUESTION_OPTION);
		$table_survey_answer 			= Database :: get_course_table(TABLE_SURVEY_ANSWER);
	
		$sql = "SELECT * FROM $table_survey_answer
					WHERE survey_id='".Database::escape_string($survey_id)."'
					AND question_id='".Database::escape_string($question_id)."'
					ORDER BY USER ASC";
		$result = api_sql_query($sql, __FILE__, __LINE__);
		while ($row = Database::fetch_array($result))
		{
			if ($row['value'] == 0)
			{
				$return[$row['user']][] = $row['option_id'];
			}
			else
			{
				$return[$row['user']][] = $row['option_id'].'*'.$row['value'];
			}
	
		}
		return $return;
	}
	
	
	/**
	 * Count the number of users who answer positively on both options
	 *
	 * @param	array	All answers of the x axis
	 * @param	array	All answers of the y axis
	 * @param	integer x axis value (= the option_id of the first question)
	 * @param	integer y axis value (= the option_id of the second question)
	 * @return	integer Number of users who have answered positively to both options
	 *
	 * @author Patrick Cool , Ghent University
	 * @version February 2007
	 */
	function comparative_check($answers_x, $answers_y, $option_x, $option_y, $value_x=0, $value_y=0)
	{
		if ($value_x==0)
		{
			$check_x = $option_x;
		}
		else
		{
			$check_x = $option_x.'*'.$value_x;
		}
		if ($value_y==0)
		{
			$check_y = $option_y;
		}
		else
		{
			$check_y = $option_y.'*'.$value_y;
		}

		$counter = 0;
		foreach ($answers_x as $user => $answers)
		{
			// check if the user has given $option_x as answer
			if (in_array($check_x, $answers))
			{
				// check if the user has given $option_y as an answer
				if (in_array($check_y, $answers_y[$user]))
				{
					$counter++;
				}
			}
		}
		return $counter;
	}
	/**
	 * Get all the information about the invitations of a certain survey
	 *
	 * @return	array	Lines of invitation [user, code, date, empty element]
	 *
	 * @author Patrick Cool , Ghent University
	 * @version January 2007
	 *
	 * @todo use survey_id parameter instead of $_GET
	 */
	function get_survey_invitations_data()
	{
		// Database table definition
		$table_survey_invitation 		= Database :: get_course_table(TABLE_SURVEY_INVITATION);
		$table_user 					= Database :: get_main_table(TABLE_MAIN_USER);
	
		$sql = "SELECT
					survey_invitation.user as col1,
					survey_invitation.invitation_code as col2,
					survey_invitation.invitation_date as col3,
					'' as col4
					FROM $table_survey_invitation survey_invitation
			LEFT JOIN $table_user user ON  survey_invitation.user = user.user_id
			WHERE survey_invitation.survey_id = '".Database::escape_string($_GET['survey_id'])."'";
		$res = api_sql_query($sql, __FILE__, __LINE__);
		while ($row = Database::fetch_array($res))
		{
			$survey_invitation_data[] = $row;
		}
		return $survey_invitation_data;
	}
	
	/**
	 * Get the total number of survey invitations for a given survey (through $_GET['survey_id'])
	 *
	 * @return	integer	Total number of survey invitations
	 *
	 * @todo use survey_id parameter instead of $_GET
	 *
	 * @author Patrick Cool , Ghent University
	 * @version January 2007
	 */
	function get_number_of_survey_invitations()
	{
		// Database table definition
		$table_survey_invitation 		= Database :: get_course_table(TABLE_SURVEY_INVITATION);
	
		$sql = "SELECT count(user) AS total FROM $table_survey_invitation WHERE survey_id='".Database::escape_string($_GET['survey_id'])."'";
		$res = api_sql_query($sql, __FILE__, __LINE__);
		$row = mysql_fetch_assoc($res);
		return $row['total'];
	}
	/**
	 * Save the invitation mail
	 *
	 * @param string 	Text of the e-mail
	 * @param integer	Whether the mail contents are for invite mail (0, default) or reminder mail (1)
	 *
	 * @author Patrick Cool , Ghent University
	 * @version January 2007
	 */
	function save_invite_mail($mailtext, $reminder=0)
	{
		// Database table definition
		$table_survey 					= Database :: get_course_table(TABLE_SURVEY);
	
		// reminder or not
		if ($reminder == 0)
		{
			$mail_field = 'invite_mail';
		}
		else
		{
			$mail_field = 'reminder_mail';
		}
	
		$sql = "UPDATE $table_survey SET $mail_field = '".Database::escape_string($mailtext)."' WHERE survey_id = '".Database::escape_string($_GET['survey_id'])."'";
		$result = api_sql_query($sql, __FILE__, __LINE__);
	}
	
	/**
	 * This function saves all the invitations of course users and additional users in the
	 *
	 * @param	array	Users array
	 * @param 	string	Title of the invitation, used as the title of the mail
	 * @param 	string	Text of the invitation, used as the text of the mail.
	 * 				 The text has to contain a **link** string or this will automatically be added to the end
	 *
	 * @author Patrick Cool , Ghent University
	 * @version January 2007
	 *
	 * @todo create the survey link
	 */
	function save_invitations($users_array, $invitation_title, $invitation_text, $reminder=0, $sendmail = 0)
	{
		global $_user;
		global $_course;
		global $_configuration;
	
		// getting the survey information
		$survey_data = survey_manager::get_survey($_GET['survey_id']);
	
		// Database table definition
		$table_survey_invitation 	= Database :: get_course_table(TABLE_SURVEY_INVITATION);
		$table_user 				= Database :: get_main_table(TABLE_MAIN_USER);
	
		$already_invited = array();
		$survey_invitations = array();
		// get the people who are already invited
		if ($reminder == 1)
		{
			$survey_invitations = SurveyUtil::get_invitations($survey_data['survey_code']);
		}
		else
		{
			$already_invited = SurveyUtil::get_invited_users($survey_data['code']);
		}
	
		$counter = 0;
		if (is_array($users_array))
		{
			foreach ($users_array as $key=>$value)
			{
				if(isset($value))
				{
					// generating the unique code
					if(is_array($survey_invitations))
					{
						if ($reminder == 1 AND array_key_exists($value,$survey_invitations))
						{
							$invitation_code = $survey_invitations[$value]['invitation_code'];
						}
						else 
						{
							$invitation_code = md5($value.microtime());
						}
					}
					$survey_link = '';
					$full_invitation_text= '';
								
					// storing the invitation (only if the user_id is not in $already_invited['course_users'] OR email is not in $already_invited['additional_users']
					$add_users_array = explode(';',$already_invited['additional_users']);
					if ((is_numeric($value) AND !in_array($value,$already_invited['course_users'])) OR (!is_numeric($value) AND !in_array($value,$add_users_array)))
					{
						if(is_array($survey_invitations))
						{
							if (!array_key_exists($value,$survey_invitations))
							{
								$sql = "INSERT INTO $table_survey_invitation (user, survey_code, invitation_code, invitation_date) VALUES
											('".Database::escape_string($value)."','".Database::escape_string($survey_data['code'])."','".Database::escape_string($invitation_code)."','".Database::escape_string(date('Y-m-d H:i:s'))."')";
								$result = api_sql_query($sql, __FILE__, __LINE__);
							}
						}
						// replacing the **link** part with a valid link for the user
						$survey_link = $_configuration['root_web'].$_configuration['code_append'].'survey/'.'fillsurvey.php?course='.$_course['sysCode'].'&invitationcode='.$invitation_code;
						$text_link = ''.get_lang('ClickHereToAnswerTheSurvey')."
\r\n
\r\n".get_lang('OrCopyPasteTheFollowingUrl')." 
\r\n ".$survey_link;
						
						$replace_count = 0;
						$full_invitation_text = str_ireplace('**link**', $text_link ,$invitation_text, $replace_count);
						if ($replace_count < 1)
						{
							$full_invitation_text = $full_invitation_text . "
\r\n
\r\n".$text_link;
						}
						
		
						// optionally: finding the e-mail of the course user
						if (is_numeric($value))
						{
							$sql = "SELECT firstname, lastname, email FROM $table_user WHERE user_id='".Database::escape_string($value)."'";
							$result = api_sql_query($sql, __FILE__, __LINE__);
							$row = Database::fetch_array($result);
							$recipient_email = $row['email'];
							$recipient_name = $row['firstname'].' '.$row['lastname'];
						}
						else
						{
							/** @todo check if the $value is a valid email	 */
							$recipient_email = $value;
						}
		
						// sending the mail
						$sender_name  = $_user['firstName'].' '.$_user['lastName'];
						$sender_email = $_user['mail'];
						
						$replyto = array();
						if(api_get_setting('survey_email_sender_noreply')=='noreply')
						{
							$noreply = api_get_setting('noreply_email_address');
							if(!empty($noreply))
							{
								$replyto['Reply-to'] = $noreply;
								$sender_name = $noreply;
								$sender_email = $noreply;
							}
						}
						if ($sendmail<>0)
						{
							api_mail_html($recipient_name, $recipient_email, $invitation_title, $full_invitation_text, $sender_name, $sender_email, $replyto);
						}
						$counter++;
					}
				}
			}
		}
	
		return $counter;
	}
	
	/**
	 * This function recalculates the number of users who have been invited and updates the survey table with this value.
	 *
	 * @param	string	Survey code
	 * @return	void
	 * @author Patrick Cool , Ghent University
	 * @version January 2007
	 */
	function update_count_invited($survey_code)
	{
		// Database table definition
		$table_survey_invitation 	= Database :: get_course_table(TABLE_SURVEY_INVITATION);
		$table_survey 				= Database :: get_course_table(TABLE_SURVEY);
	
		// counting the number of people that are invited
		$sql = "SELECT count(user) as total FROM $table_survey_invitation WHERE survey_code = '".Database::escape_string($survey_code)."'";
		$result = api_sql_query($sql, __FILE__, __LINE__);
		$row = Database::fetch_array($result);
		$total_invited = $row['total'];
	
		// updating the field in the survey table
		$sql = "UPDATE $table_survey SET invited = '".Database::escape_string($total_invited)."' WHERE code = '".Database::escape_string($survey_code)."'";
		$result = api_sql_query($sql, __FILE__, __LINE__);
	}
	
	/**
	 * This function gets all the invited users for a given survey code.
	 *
	 * @param	string	Survey code
	 * @return 	array	Array containing the course users and additional users (non course users)
	 *
	 * @todo consider making $defaults['additional_users'] also an array
	 *
	 * @author Patrick Cool , Ghent University
	 * @version January 2007
	 */
	function get_invited_users($survey_code)
	{
		// Database table definition
		$table_survey_invitation 	= Database :: get_course_table(TABLE_SURVEY_INVITATION);
	
		// Selecting all the invitations of this survey
		$sql = "SELECT user FROM $table_survey_invitation WHERE survey_code='".Database::escape_string($survey_code)."'";
	
		$defaults = array();
		$defaults['course_users'] = array();
		$defaults['additional_users'] = '';
		$result = api_sql_query($sql, __FILE__, __LINE__);
		while ($row = Database::fetch_array($result))
		{
			if (is_numeric($row['user']))
			{
				$defaults['course_users'][] = $row['user'];
			}
			else
			{
				if (empty($defaults['additional_users']))
				{
					$defaults['additional_users'] = $row['user'];
				}
				else
				{
					$defaults['additional_users'] .= ';'.$row['user'];
				}
			}
		}
		return $defaults;
	}
	/**
	 * Get all the invitations
	 *
	 * @param	string	Survey code
	 * @return	array	Database rows matching the survey code
	 *
	 * @author Patrick Cool , Ghent University
	 * @version September 2007
	 */
	function get_invitations($survey_code)
	{
		// Database table definition
		$table_survey_invitation 	= Database :: get_course_table(TABLE_SURVEY_INVITATION);
	
		$sql = "SELECT * FROM $table_survey_invitation WHERE survey_code = '".Database::escape_string($survey_code)."'";
		$result = api_sql_query($sql, __FILE__, __LINE__);
		$return = array();
		while ($row = Database::fetch_array($result))
		{
			$return[$row['user']] = $row;
		}
		return $return;
	}
	/**
	 * This function displays the form for searching a survey
	 *
	 * @return	void	(direct output)
	 *
	 * @author Patrick Cool , Ghent University
	 * @version January 2007
	 *
	 * @todo use quickforms
	 * @todo consider moving this to surveymanager.inc.lib.php
	 */
	function display_survey_search_form()
	{
		echo '
';
		echo '

				

					
'.get_lang('Title').'
					

				
				

					
'.get_lang('Code').'
					

				
				

					
'.get_lang('Language').'
					

						'.get_lang('All').'';
		$languages = api_get_languages();
		foreach ($languages['name'] as $index => $name)
		{
			echo ''.$name.'';
		}
		echo '			
					
				
				

					
 
					

				
			
		
';
	}
	
	/**
	 * This function displays the sortable table with all the surveys
	 *
	 * @return	void	(direct output)
	 *
	 * @author Patrick Cool , Ghent University
	 * @version January 2007
	 */
	function display_survey_list()
	{
		$parameters = array();
		if ($_GET['do_search'])
		{
			$message = get_lang('DisplaySearchResults').'
';
			$message .= ''.get_lang('DisplayAll').'';
			Display::display_normal_message($message, false);
		}
	
		// Create a sortable table with survey-data
		$table = new SortableTable('surveys', 'get_number_of_surveys', 'get_survey_data',2);
		$table->set_additional_parameters($parameters);
		$table->set_header(0, '', false);
		$table->set_header(1, get_lang('SurveyName'));
		$table->set_header(2, get_lang('SurveyCode'));
		$table->set_header(3, get_lang('NumberOfQuestions'));
		$table->set_header(4, get_lang('Author'));
		$table->set_header(5, get_lang('Language'));
		$table->set_header(6, get_lang('Shared'));
		$table->set_header(7, get_lang('AvailableFrom'));
		$table->set_header(8, get_lang('AvailableUntill'));
		$table->set_header(9, get_lang('Invite'));
		$table->set_header(10, get_lang('Anonymous'));
		$table->set_header(11, get_lang('Modify'), false);
		$table->set_column_filter(10, 'anonymous_filter');
		$table->set_column_filter(11, 'modify_filter');
		$table->set_form_actions(array ('delete' => get_lang('DeleteSurvey')));
		$table->display();
	
	}
	
	/**
	 * This function changes the modify column of the sortable table
	 *
	 * @param integer $survey_id the id of the survey
	 * @return html code that are the actions that can be performed on any survey
	 *
	 * @author Patrick Cool , Ghent University
	 * @version January 2007
	 */
	function modify_filter($survey_id)
	{
		global $charset;
		$survey_id = Security::remove_XSS($survey_id);
		$return = ''.Display::return_icon('edit.gif', get_lang('Edit')).'';
		$return .= ''.Display::return_icon('delete.gif', get_lang('Delete')).'';
		//$return .= ''.Display::return_icon('copy.gif', get_lang('Copy')).'';
		//$return .= ''.Display::return_icon('add.gif', get_lang('Add')).'';
		$return .= ''.Display::return_icon('preview.gif', get_lang('Preview')).'';
		$return .= ''.Display::return_icon('survey_publish.gif', get_lang('Publish')).'';
		$return .= ''.Display::return_icon('empty.gif', get_lang('EmptySurvey')).'';
		$return .= ''.Display::return_icon('statistics.gif', get_lang('Reporting')).'';
		return $return;
	}
	/**
	 * Returns "yes" when given parameter is one, "no" for any other value
	 * @param	integer	Whether anonymous or not
	 * @return	string	"Yes" or "No" in the current language
	 */
	function anonymous_filter($anonymous)
	{
		if ($anonymous == 1)
		{
			return get_lang('Yes');
		}
		else
		{
			return get_lang('No');
		}
	}
	
	
	/**
	 * This function handles the search restriction for the SQL statements
	 *
	 * @return	string	Part of a SQL statement or false on error
	 *
	 * @author Patrick Cool , Ghent University
	 * @version January 2007
	 */
	function survey_search_restriction()
	{
		if ($_GET['do_search'])
		{
			if ($_GET['keyword_title']<>'')
			{
				$search_term[] = 'title =\''.Database::escape_string($_GET['keyword_title']).'\'';
			}
			if ($_GET['keyword_code']<>'')
			{
				$search_term[] = 'code =\''.Database::escape_string($_GET['keyword_code']).'\'';
			}
			if ($_GET['keyword_language']<>'%')
			{
				$search_term[] = 'lang =\''.Database::escape_string($_GET['keyword_language']).'\'';
			}
	
			$search_restriction = implode(' AND ', $search_term);
			return $search_restriction;
		}
		else
		{
			return false;
		}
	}
	/**
	 * This function calculates the total number of surveys
	 *
	 * @return	integer	Total number of surveys
	 *
	 * @author Patrick Cool , Ghent University
	 * @version January 2007
	 */
	function get_number_of_surveys()
	{
		global $table_survey;
	
		$search_restriction = SurveyUtil::survey_search_restriction();
		if ($search_restriction)
		{
			$search_restriction = 'WHERE '.$search_restriction;
		}
	
		$sql = "SELECT count(survey_id) AS total_number_of_items FROM ".$table_survey.' '.$search_restriction;
		$res = api_sql_query($sql, __FILE__, __LINE__);
		$obj = Database::fetch_object($res);
		return $obj->total_number_of_items;
	
	}
	
	/**
	 * This function gets all the survey data that is to be displayed in the sortable table
	 *
	 * @param unknown_type $from
	 * @param unknown_type $number_of_items
	 * @param unknown_type $column
	 * @param unknown_type $direction
	 * @return unknown
	 *
	 * @author Patrick Cool , Ghent University
	 * @version January 2007
	 */
	function get_survey_data($from, $number_of_items, $column, $direction)
	{
		global $table_survey;
		global $table_user;
		global $table_survey_question;
	
		// searching
		$search_restriction = SurveyUtil::survey_search_restriction();
		if ($search_restriction)
		{
			$search_restriction = ' AND '.$search_restriction;
		}
		$sql = "SELECT
					survey.survey_id							AS col0,
	                CONCAT('',survey.title,'')		AS col1,
					survey.code									AS col2,
					count(survey_question.question_id)			AS col3,
	                CONCAT(user.firstname, ' ', user.lastname)	AS col4,
	                survey.lang									AS col5,
	                IF(is_shared<>0,'V','-')	 					AS col6,
					survey.avail_from							AS col7,
	                survey.avail_till							AS col8,
	                CONCAT('',survey.answered,' / ',survey.invited, '')	AS col9,
	                survey.anonymous							AS col10,
	                survey.survey_id							AS col11
	             FROM $table_survey survey
				 LEFT JOIN $table_survey_question survey_question ON survey.survey_id = survey_question.survey_id
	             , $table_user user
	             WHERE survey.author = user.user_id
	             $search_restriction
	             ";
		$sql .= " GROUP BY survey.survey_id";
		$sql .= " ORDER BY col$column $direction ";
		$sql .= " LIMIT $from,$number_of_items";
		$res = api_sql_query($sql, __FILE__, __LINE__);
		$surveys = array ();
		while ($survey = Database::fetch_array($res))
		{
			$surveys[] = $survey;
		}
		return $surveys;
	}
	
	/**
	 * Display all the active surveys for the given course user
	 *
	 * @param unknown_type $user_id
	 * 
	 * @author Patrick Cool , Ghent University
	 * @version April 2007
	 */
	function survey_list_user($user_id)
	{
		global $_course;	
	
		// Database table definitions
		$table_survey_invitation = Database :: get_course_table(TABLE_SURVEY_INVITATION);
		$table_survey_answer = Database :: get_course_table(TABLE_SURVEY_ANSWER);
		$table_survey 			= Database :: get_course_table(TABLE_SURVEY);
		$table_user 			= Database :: get_main_table(TABLE_MAIN_USER);
	
		$sql = "SELECT * FROM $table_survey survey, $table_survey_invitation survey_invitation
				WHERE survey_invitation.user = '".Database::escape_string($user_id)."'
				AND survey.code = survey_invitation.survey_code
				AND survey.avail_from <= '".date('Y-m-d H:i:s')."'
				AND survey.avail_till >= '".date('Y-m-d H:i:s')."'
				";
	
		$result = api_sql_query($sql, __FILE__, __LINE__);
		
		echo '';
		echo '';
		echo '	';
		echo '	';
		echo '';
		
		$counter = 0;
		while ($row = Database::fetch_array($result,'ASSOC'))
		{
			echo '';
			if ($row['answered'] == 0)
			{
				echo '';
			}
			else 
			{
				echo '';
			}
			echo '';
			echo '';
		}
		echo '
'.get_lang('SurveyName').'
'.get_lang('Anonymous').'
'.$row['title'].'
'.$row['title'].'
';
			echo ($row['anonymous'] == 1)?get_lang('Yes'):get_lang('No');
			echo '
';
	}	
}
?>