diff --git a/main/admin/class_add.php b/main/admin/class_add.php
index 92632dda45..0ca969e200 100644
--- a/main/admin/class_add.php
+++ b/main/admin/class_add.php
@@ -29,48 +29,43 @@
 ==============================================================================
 */
 
-// name of the language file that needs to be included
+// Language files that should be included.
 $language_file = 'admin';
 
-// resetting the course id
+// Resetting the course id.
 $cidReset = true;
 
-// including some necessary dokeos files
-require_once('../inc/global.inc.php');
-require_once (api_get_path(LIBRARY_PATH).'classmanager.lib.php');
-require_once (api_get_path(LIBRARY_PATH).'formvalidator/FormValidator.class.php');
+// Including some necessary dokeos files.
+require_once '../inc/global.inc.php';
+require_once api_get_path(LIBRARY_PATH).'classmanager.lib.php';
+require_once api_get_path(LIBRARY_PATH).'formvalidator/FormValidator.class.php';
 
-// setting the section (for the tabs)
+// Setting the section (for the tabs).
 $this_section = SECTION_PLATFORM_ADMIN;
 
-// Access restrictions
+// Access restrictions.
 api_protect_admin_script();
 
-// setting breadcrumbs
+// Setting breadcrumbs.
 $interbreadcrumb[] = array('url' => 'index.php', 'name' => get_lang('PlatformAdmin'));
 
-// setting the name of the tool
+// Setting the name of the tool.
 $tool_name = get_lang("AddClasses");
 
 $form = new FormValidator('add_class');
-$form->add_textfield('name',get_lang('ClassName'));
-$form->addElement('submit','submit',get_lang('Ok'));
-if($form->validate())
-{
+$form->add_textfield('name', get_lang('ClassName'));
+$form->addElement('style_submit_button', 'submit', get_lang('Ok'), 'class="add"');
+if ($form->validate()) {
 	$values = $form->exportValues();
-	ClassManager :: create_class($values['name']);
+	ClassManager::create_class($values['name']);
 	header('Location: class_list.php');
 }
 
-// Displaying the header
+// Displaying the header.
 Display :: display_header($tool_name);
 
-// Displaying the form
+// Displaying the form.
 $form->display();
-/*
-==============================================================================
-		FOOTER
-==============================================================================
-*/
+
+// Displaying the footer.
 Display :: display_footer();
-?>
\ No newline at end of file
diff --git a/main/admin/class_edit.php b/main/admin/class_edit.php
index 231f046a35..98b2c80b79 100644
--- a/main/admin/class_edit.php
+++ b/main/admin/class_edit.php
@@ -29,37 +29,36 @@
 ==============================================================================
 */
 
-// name of the language file that needs to be included
+// Language files that should be included.
 $language_file = 'admin';
 
-// resetting the course id
+// Resetting the course id.
 $cidReset = true;
 
-// including some necessary dokeos files
-include ('../inc/global.inc.php');
-require_once(api_get_path(LIBRARY_PATH).'classmanager.lib.php');
-require_once (api_get_path(LIBRARY_PATH).'formvalidator/FormValidator.class.php');
+// Including some necessary dokeos files.
+include '../inc/global.inc.php';
+require_once api_get_path(LIBRARY_PATH).'classmanager.lib.php';
+require_once api_get_path(LIBRARY_PATH).'formvalidator/FormValidator.class.php';
 
-// setting the section (for the tabs)
-$this_section=SECTION_PLATFORM_ADMIN;
+// Setting the section (for the tabs).
+$this_section = SECTION_PLATFORM_ADMIN;
 
-// Access restrictions
+// Access restrictions.
 api_protect_admin_script();
 
-// setting breadcrumbs
-$interbreadcrumb[] = array ("url" => 'index.php', "name" => get_lang('PlatformAdmin'));
-$interbreadcrumb[] = array ("url" => "class_list.php", "name" => get_lang('AdminClasses'));
-
-// setting the name of the tool
-$tool_name = get_lang("AddClasses");
+// Setting breadcrumbs.
+$interbreadcrumb[] = array ('url' => 'index.php', 'name' => get_lang('PlatformAdmin'));
+$interbreadcrumb[] = array ('url' => 'class_list.php', 'name' => get_lang('AdminClasses'));
 
+// Setting the name of the tool.
+$tool_name = get_lang('AddClasses');
 
 $tool_name = get_lang('ModifyClassInfo');
 $class_id = intval($_GET['idclass']);
 $class = ClassManager :: get_class_info($class_id);
-$form = new FormValidator('edit_class','post','class_edit.php?idclass='.$class_id);
+$form = new FormValidator('edit_class', 'post', 'class_edit.php?idclass='.$class_id);
 $form->add_textfield('name',get_lang('ClassName'));
-$form->addElement('submit','submit',get_lang('Ok'));
+$form->addElement('style_submit_button', 'submit', get_lang('Ok'), 'class="add"');
 $form->setDefaults(array('name'=>$class['name']));
 if($form->validate())
 {
@@ -68,14 +67,9 @@ if($form->validate())
 	header('Location: class_list.php');
 }
 
-
 Display :: display_header($tool_name);
 //api_display_tool_title($tool_name);
 $form->display();
-/*
-==============================================================================
-		FOOTER
-==============================================================================
-*/
+
+// Displaying the footer.
 Display :: display_footer();
-?>
\ No newline at end of file
diff --git a/main/admin/class_import.php b/main/admin/class_import.php
index b9f121fadd..6cc37427cc 100644
--- a/main/admin/class_import.php
+++ b/main/admin/class_import.php
@@ -30,100 +30,91 @@
 *	@package dokeos.admin
 ==============================================================================
 */
+
 /**
- * Validate the imported data
+ * Validates imported data.
  */
-function validate_data($classes)
-{
+function validate_data($classes) {
 	$errors = array();
-	foreach($classes as $index => $class)
-	{
-		//1. Check if ClassName is available
-		if(!isset($class['ClassName']) || strlen(trim($class['ClassName'])) == 0)
-		{
-			$class['line'] = $index+2;
+	foreach ($classes as $index => $class) {
+		// 1. Check wheter ClassName is available.
+		if (!isset($class['ClassName']) || strlen(trim($class['ClassName'])) == 0) {
+			$class['line'] = $index + 2;
 			$class['error'] = get_lang('MissingClassName');
 			$errors[] = $class;
 		}
-		//2. Check if class doesn't exist yet
-		else
-		{
-			if(ClassManager::class_name_exists($class['ClassName']))
-			{
-				$class['line'] = $index+2;
-				$class['error'] = get_lang('ClassNameExists');
+		// 2. Check whether class doesn't exist yet.
+		else {
+			if (ClassManager::class_name_exists($class['ClassName'])) {
+				$class['line'] = $index + 2;
+				$class['error'] = get_lang('ClassNameExists').' <strong>'.$class['ClassName'].'</strong>';
 				$errors[] = $class;
 			}
 		}
 	}
 	return $errors;
 }
+
 /**
  * Save imported class data to database
  */
-function save_data($classes)
-{
+function save_data($classes) {
 	$number_of_added_classes = 0;
-	foreach($classes as $index => $class)
-	{
-		if(ClassManager::create_class($class['ClassName']))
-		{
+	foreach ($classes as $index => $class) {
+		if (ClassManager::create_class($class['ClassName'])) {
 			$number_of_added_classes++;
 		}
 	}
 	return $number_of_added_classes;
 }
 
-
-
-// name of the language file that needs to be included
+// Language files that should be included.
 $language_file = array ('admin', 'registration');
 
-// resetting the course id
+// Resetting the course id.
 $cidReset = true;
 
-// including some necessary dokeos files
-include ('../inc/global.inc.php');
-require_once (api_get_path(LIBRARY_PATH).'fileManage.lib.php');
-require_once (api_get_path(LIBRARY_PATH).'classmanager.lib.php');
-require_once (api_get_path(LIBRARY_PATH).'import.lib.php');
-require_once (api_get_path(LIBRARY_PATH).'formvalidator/FormValidator.class.php');
+// Including some necessary dokeos files.
+include '../inc/global.inc.php';
+require_once api_get_path(LIBRARY_PATH).'fileManage.lib.php';
+require_once api_get_path(LIBRARY_PATH).'classmanager.lib.php';
+require_once api_get_path(LIBRARY_PATH).'import.lib.php';
+require_once api_get_path(LIBRARY_PATH).'formvalidator/FormValidator.class.php';
 
-// setting the section (for the tabs)
+// Setting the section (for the tabs).
 $this_section = SECTION_PLATFORM_ADMIN;
 
-// Access restrictions
+// Access restrictions.
 api_protect_admin_script();
 
 // setting breadcrumbs
-$interbreadcrumb[] = array ("url" => 'index.php', "name" => get_lang('PlatformAdmin'));
+$interbreadcrumb[] = array ('url' => 'index.php', 'name' => get_lang('PlatformAdmin'));
 
 // Database Table Definitions
 
-// setting the name of the tool
+// Setting the name of the tool.
 $tool_name = get_lang('ImportClassListCSV');
 
-// Displaying the header
+// Displaying the header.
 Display :: display_header($tool_name);
 //api_display_tool_title($tool_name);
+
+set_time_limit(0);
+
 $form = new FormValidator('import_classes');
-$form->addElement('file','import_file',get_lang('ImportCSVFileLocation'));
-$form->addElement('submit','submit',get_lang('Ok'));
-if( $form->validate())
-{
+$form->addElement('file', 'import_file', get_lang('ImportCSVFileLocation'));
+$form->addElement('style_submit_button', 'submit', get_lang('Import'), 'class="save"');
+
+if ($form->validate()) {
 	$classes = Import::csv_to_array($_FILES['import_file']['tmp_name']);
 	$errors = validate_data($classes);
-	if (count($errors) == 0)
-	{
+	if (count($errors) == 0) {
 		$number_of_added_classes = save_data($classes);
 		Display::display_normal_message($number_of_added_classes.' '.get_lang('ClassesCreated'));
-	}
-	else
-	{
+	} else {
 		$error_message = get_lang('ErrorsWhenImportingFile');
 		$error_message .= '<ul>';
-		foreach ($errors as $index => $error_class)
-		{
+		foreach ($errors as $index => $error_class) {
 			$error_message .= '<li>'.$error_class['error'].' ('.get_lang('Line').' '.$error_class['line'].')';
 			$error_message .= '</li>';
 		}
@@ -132,7 +123,9 @@ if( $form->validate())
 		Display :: display_error_message($error_message);
 	}
 }
+
 $form->display();
+
 ?>
 <p><?php echo get_lang('CSVMustLookLike').' ('.get_lang('MandatoryFields').')'; ?> :</p>
 <blockquote>
@@ -145,10 +138,6 @@ $form->display();
  </pre>
 </blockquote>
 <?php
-/*
-==============================================================================
-		FOOTER
-==============================================================================
-*/
+
+// Displaying the footer.
 Display :: display_footer();
-?>
\ No newline at end of file
diff --git a/main/admin/class_information.php b/main/admin/class_information.php
index 0188d2de82..1e1c743d77 100644
--- a/main/admin/class_information.php
+++ b/main/admin/class_information.php
@@ -28,43 +28,39 @@
 ==============================================================================
 */
 
-/*
-==============================================================================
-		INIT SECTION
-==============================================================================
-*/
-
-// name of the language file that needs to be included
-$language_file='admin';
+// Language files that should be included.
+$language_file = 'admin';
 
-$cidReset=true;
+$cidReset = true;
 
-require('../inc/global.inc.php');
-$this_section=SECTION_PLATFORM_ADMIN;
+require '../inc/global.inc.php';
+$this_section = SECTION_PLATFORM_ADMIN;
 
 api_protect_admin_script();
-require(api_get_path(LIBRARY_PATH).'classmanager.lib.php');
-if( !isset($_GET['id']))
-{
+
+require api_get_path(LIBRARY_PATH).'classmanager.lib.php';
+
+if (!isset($_GET['id'])) {
 	api_not_allowed();
 }
-$interbreadcrumb[] = array ("url" => 'index.php', "name" => get_lang('PlatformAdmin'));
-$interbreadcrumb[] = array ("url" => 'class_list.php', "name" => get_lang('AdminClasses'));
+
+$interbreadcrumb[] = array ('url' => 'index.php', 'name' => get_lang('PlatformAdmin'));
+$interbreadcrumb[] = array ('url' => 'class_list.php', 'name' => get_lang('AdminClasses'));
+
 $class_id = $_GET['id'];
 $class = ClassManager::get_class_info($class_id);
 
 $tool_name = $class['name'];
 Display::display_header($tool_name);
 //api_display_tool_title($tool_name);
+
 /**
- * Show all users subscribed in this class
+ * Show all users subscribed in this class.
  */
 echo '<h4>'.get_lang('Users').'</h4>';
 echo '<blockquote>';
-
 $users = ClassManager::get_users($class_id);
-if (count($users) > 0)
-{
+if (count($users) > 0) {
 	$is_western_name_order = api_is_western_name_order();
 	$table_header[] = array (get_lang('OfficialCode'), true);
 	if ($is_western_name_order) {
@@ -78,8 +74,7 @@ if (count($users) > 0)
 	$table_header[] = array (get_lang('Status'), true);
 	$table_header[] = array ('', false);
 	$data = array();
-	foreach($users as $index => $user)
-	{
+	foreach($users as $index => $user) {
 		$row = array ();
 		$row[] = $user['official_code'];
 		if ($is_western_name_order) {
@@ -95,24 +90,21 @@ if (count($users) > 0)
 		$data[] = $row;
 	}
 	Display::display_sortable_table($table_header,$data,array(),array(),array('id'=>$_GET['id']));
-}
-else
-{
+} else {
 	echo get_lang('NoUsersInClass');
 }
 echo '</blockquote>';
+
 /**
- * Show all courses in which this class is subscribed
+ * Show all courses in which this class is subscribed.
  */
 $courses = ClassManager::get_courses($class_id);
-if (count($courses) > 0)
-{
+if (count($courses) > 0) {
 	$header[] = array (get_lang('Code'), true);
 	$header[] = array (get_lang('Title'), true);
 	$header[] = array ('', false);
 	$data = array ();
-	foreach( $courses as $index=>$course)
-	{
+	foreach( $courses as $index => $course) {
 		$row = array ();
 		$row[] = $course['visual_code'];
 		$row[] = $course['title'];
@@ -125,15 +117,9 @@ if (count($courses) > 0)
 	echo '<blockquote>';
 	Display :: display_sortable_table($header, $data, array (), array (), array('id'=>$_GET['id']));
 	echo '</blockquote>';
-}
-else
-{
+} else {
 	echo '<p>'.get_lang('NoCoursesForThisClass').'</p>';
 }
-/*
-==============================================================================
-		FOOTER
-==============================================================================
-*/
+
+// Displaying the footer.
 Display::display_footer();
-?>
\ No newline at end of file
diff --git a/main/admin/class_list.php b/main/admin/class_list.php
index c7f3cbb6c7..8810a63487 100644
--- a/main/admin/class_list.php
+++ b/main/admin/class_list.php
@@ -28,36 +28,36 @@
 ==============================================================================
 */
 
-// name of the language file that needs to be included
 $language_file = 'admin';
+
 $cidReset = true;
-require ('../inc/global.inc.php');
+require '../inc/global.inc.php';
+
 $this_section = SECTION_PLATFORM_ADMIN;
+api_protect_admin_script();
 
 /**
- * Gets the total number of classes
+ * Gets the total number of classes.
  */
-function get_number_of_classes()
-{
+function get_number_of_classes() {
 	$tbl_class = Database :: get_main_table(TABLE_MAIN_CLASS);
 	$sql = "SELECT COUNT(*) AS number_of_classes FROM $tbl_class";
-	if (isset ($_GET['keyword']))
-	{
+	if (isset ($_GET['keyword'])) {
 		$sql .= " WHERE (name LIKE '%".Database::escape_string(trim($_GET['keyword']))."%')";
 	}
-	$res = api_sql_query($sql, __FILE__, __LINE__);
+	$res = Database::query($sql, __FILE__, __LINE__);
 	$obj = Database::fetch_object($res);
 	return $obj->number_of_classes;
 }
+
 /**
- * Gets the information about some classes
+ * Gets the information about some classes.
  * @param int $from
  * @param int $number_of_items
  * @param string $direction
  */
-function get_class_data($from, $number_of_items, $column, $direction)
-{
-	$tbl_class_user = Database :: get_main_table(TABLE_MAIN_CLASS_USER);
+function get_class_data($from, $number_of_items, $column, $direction) {
+	$tbl_class_user = Database::get_main_table(TABLE_MAIN_CLASS_USER);
 	$tbl_class = Database :: get_main_table(TABLE_MAIN_CLASS);
 	$from 				= Database::escape_string($from);
 	$number_of_items 	= Database::escape_string($number_of_items);
@@ -65,55 +65,49 @@ function get_class_data($from, $number_of_items, $column, $direction)
 	$direction 			= Database::escape_string($direction);
 
 	$sql = "SELECT 	id AS col0, name AS col1, COUNT(user_id) AS col2, id AS col3
-				FROM $tbl_class
-				LEFT JOIN $tbl_class_user ON id=class_id ";
-	if (isset ($_GET['keyword']))
-	{
+		FROM $tbl_class
+			LEFT JOIN $tbl_class_user ON id=class_id ";
+	if (isset ($_GET['keyword'])) {
 		$sql .= " WHERE (name LIKE '%".Database::escape_string(trim($_GET['keyword']))."%')";
 	}
-	$sql .= "GROUP BY id,name ORDER BY col$column $direction LIMIT $from,$number_of_items";
-	$res = api_sql_query($sql, __FILE__, __LINE__);
+	$sql .= " GROUP BY id,name ORDER BY col$column $direction LIMIT $from,$number_of_items";
+	$res = Database::query($sql, __FILE__, __LINE__);
 	$classes = array ();
-	while ($class = Database::fetch_row($res))
-	{
+	while ($class = Database::fetch_row($res)) {
 		$classes[] = $class;
 	}
 	return $classes;
 }
+
 /**
  * Filter for sortable table to display edit icons for class
  */
-function modify_filter($class_id)
-{
-	global $charset;
+function modify_filter($class_id) {
 	$class_id = Security::remove_XSS($class_id);
 	$result = '<a href="class_information.php?id='.$class_id.'">'.Display::return_icon('synthese_view.gif', get_lang('Info')).'</a>';
 	$result .= '<a href="class_edit.php?idclass='.$class_id.'">'.Display::return_icon('edit.gif', get_lang('Edit')).'</a>';
-	$result .= '<a href="class_list.php?action=delete_class&amp;class_id='.$class_id.'" onclick="javascript:if(!confirm('."'".addslashes(api_htmlentities(get_lang("ConfirmYourChoice"),ENT_QUOTES,$charset))."'".')) return false;">'.Display::return_icon('delete.gif', get_lang('Delete')).'</a>';
+	$result .= '<a href="class_list.php?action=delete_class&amp;class_id='.$class_id.'" onclick="javascript: if(!confirm('."'".addslashes(api_htmlentities(get_lang("ConfirmYourChoice"), ENT_QUOTES))."'".')) return false;">'.Display::return_icon('delete.gif', get_lang('Delete')).'</a>';
 	$result .= '<a href="subscribe_user2class.php?idclass='.$class_id.'">'.Display::return_icon('add_multiple_users.gif', get_lang('AddUsersToAClass')).'</a>';
 	return $result;
 }
 
-api_protect_admin_script();
-require (api_get_path(LIBRARY_PATH).'fileManage.lib.php');
-require (api_get_path(LIBRARY_PATH).'classmanager.lib.php');
-require_once (api_get_path(LIBRARY_PATH).'formvalidator/FormValidator.class.php');
+require api_get_path(LIBRARY_PATH).'fileManage.lib.php';
+require api_get_path(LIBRARY_PATH).'classmanager.lib.php';
+require_once api_get_path(LIBRARY_PATH).'formvalidator/FormValidator.class.php';
+
 $tool_name = get_lang('ClassList');
-$interbreadcrumb[] = array ("url" => 'index.php', "name" => get_lang('PlatformAdmin'));
+$interbreadcrumb[] = array ('url' => 'index.php', 'name' => get_lang('PlatformAdmin'));
 
 Display :: display_header($tool_name);
 //api_display_tool_title($tool_name);
-if (isset ($_POST['action']))
-{
-	switch ($_POST['action'])
-	{
+
+if (isset($_POST['action'])) {
+	switch ($_POST['action']) {
 		// Delete selected classes
 		case 'delete_classes' :
 			$classes = $_POST['class'];
-			if (count($classes) > 0)
-			{
-				foreach ($classes as $index => $class_id)
-				{
+			if (count($classes) > 0) {
+				foreach ($classes as $index => $class_id) {
 					ClassManager :: delete_class($class_id);
 				}
 				Display :: display_normal_message(get_lang('ClassesDeleted'));
@@ -121,36 +115,37 @@ if (isset ($_POST['action']))
 			break;
 	}
 }
-if (isset ($_GET['action']))
-{
-	switch ($_GET['action'])
-	{
-		case 'delete_class' :
+
+if (isset($_GET['action'])) {
+	switch ($_GET['action']) {
+		case 'delete_class':
 			ClassManager :: delete_class($_GET['class_id']);
 			Display :: display_normal_message(get_lang('ClassDeleted'));
+			break;
+		case 'show_message':
+			Display :: display_normal_message(Security::remove_XSS(stripslashes($_GET['message'])));
+			break;
 	}
 }
+
 // Create a search-box
-$form = new FormValidator('search_simple','get','','',null,false);
+$form = new FormValidator('search_simple', 'get', '', '', null, false);
 $renderer =& $form->defaultRenderer();
 $renderer->setElementTemplate('<span>{element}</span> ');
-$form->addElement('text','keyword',get_lang('keyword'));
-$form->addElement('submit','submit',get_lang('Search'));
+$form->addElement('text', 'keyword', get_lang('keyword'));
+$form->addElement('submit', 'submit', get_lang('Search'));
 $form->display();
+
 // Create the sortable table with class information
 $table = new SortableTable('classes', 'get_number_of_classes', 'get_class_data', 1);
-$table->set_additional_parameters(array('keyword'=>$_GET['keyword']));
+$table->set_additional_parameters(array('keyword' => $_GET['keyword']));
 $table->set_header(0, '', false);
 $table->set_header(1, get_lang('ClassName'));
 $table->set_header(2, get_lang('NumberOfUsers'));
 $table->set_header(3, '', false);
 $table->set_column_filter(3, 'modify_filter');
-$table->set_form_actions(array ('delete_classes' => get_lang('DeleteSelectedClasses')),'class');
+$table->set_form_actions(array ('delete_classes' => get_lang('DeleteSelectedClasses')), 'class');
 $table->display();
-/*
-==============================================================================
-		FOOTER
-==============================================================================
-*/
+
+// Displaying the footer.
 Display :: display_footer();
-?>