diff --git a/main/admin/add_users_to_session.php b/main/admin/add_users_to_session.php
index a81b2b852b..d208f0eb83 100644
--- a/main/admin/add_users_to_session.php
+++ b/main/admin/add_users_to_session.php
@@ -49,7 +49,7 @@ api_protect_admin_script(true);
 
 // setting breadcrumbs
 $interbreadcrumb[]=array('url' => 'index.php','name' => get_lang('PlatformAdmin'));
-$interbreadcrumb[]=array('url' => "session_list.php","name" => get_lang('SessionList'));
+$interbreadcrumb[]=array('url' => 'session_list.php','name' => get_lang('SessionList'));
 
 // Database Table Definitions
 $tbl_session						= Database::get_main_table(TABLE_MAIN_SESSION);
@@ -68,8 +68,8 @@ $tool_name=get_lang('SubscribeUsersToSession');
 $id_session=intval($_GET['id_session']);
 
 $add_type = 'unique';
-if(isset($_GET['add_type']) && $_GET['add_type']!=''){
-	$add_type = $_GET['add_type'];
+if(isset($_REQUEST['add_type']) && $_REQUEST['add_type']!=''){
+	$add_type = $_REQUEST['add_type'];
 }
 
 if(!api_is_platform_admin()) {
@@ -80,6 +80,19 @@ if(!api_is_platform_admin()) {
 	}
 }
 
+//checking for extra field with filter on
+include_once (api_get_path(LIBRARY_PATH).'usermanager.lib.php');
+$extra_field_list= UserManager::get_extra_fields();
+$new_field_list = array();
+if (is_array($extra_field_list)) {
+	foreach ($extra_field_list as $extra_field) {
+		//if is enabled to filter and is a "<select>" field type
+		if ($extra_field[8]==1 && $extra_field[2]==4 ) {
+			$new_field_list[] = array('name'=> $extra_field[1], 'variable'=>$extra_field[1], 'data'=> $extra_field[9]);
+		}
+	}
+}	
+	
 
 function search_users($needle)
 {
@@ -165,17 +178,28 @@ function remove_item(origin)
 		}
 	}
 }
+
+function validate_filter() {
+	
+		document.formulaire.add_type.value = \''.$add_type.'\';
+		document.formulaire.form_sent.value=0;				
+		document.formulaire.submit();
+		
+}
+			
+
+	
 </script>';
 
 
-$formSent=0;
+$form_sent=0;
 $errorMsg=$firstLetterUser=$firstLetterSession='';
 $UserList=$SessionList=array();
 $users=$sessions=array();
 $noPHP_SELF=true;
 
-if($_POST['formSent']) {
-	$formSent=$_POST['formSent'];
+if($_POST['form_sent']) {
+	$form_sent=$_POST['form_sent'];
 	$firstLetterUser=$_POST['firstLetterUser'];
 	$firstLetterSession=$_POST['firstLetterSession'];
 	$UserList=$_POST['sessionUsersList'];
@@ -184,7 +208,7 @@ if($_POST['formSent']) {
 		$UserList=array();
 	}
 
-	if ($formSent == 1) {
+	if ($form_sent == 1) {
 		$sql = "SELECT id_user FROM $tbl_session_rel_user WHERE id_session='$id_session'";
 		$result = api_sql_query($sql,__FILE__,__LINE__);
 		$existingUsers = array();
@@ -256,7 +280,6 @@ if($_POST['formSent']) {
 			//header('Location: '.$_GET['page'].'?id_session='.$id_session);
 		//else
 		header('Location: resume_session.php?id_session='.$id_session);
-
 	}
 }
 
@@ -268,6 +291,7 @@ $nosessionUsersList = $sessionUsersList = array();
 $rs = api_sql_query($sql, __FILE__, __LINE__);
 $count_courses = Database::result($rs, 0, 0);*/
 $ajax_search = $add_type == 'unique' ? true : false;
+global $_configuration;	
 
 if ($ajax_search) {
 	$sql="SELECT user_id, lastname, firstname, username, id_session
@@ -276,8 +300,7 @@ if ($ajax_search) {
 				ON $tbl_session_rel_user.id_user = $tbl_user.user_id
 				AND $tbl_session_rel_user.id_session = ".intval($id_session)."
 			ORDER BY lastname,firstname,username";
-			
-	global $_configuration;	
+	
 	if ($_configuration['multiple_access_urls']==true) {		
 		$tbl_user_rel_access_url= Database::get_main_table(TABLE_MAIN_ACCESS_URL_REL_USER);	
 		$access_url_id = api_get_current_access_url_id();
@@ -291,23 +314,78 @@ if ($ajax_search) {
 				WHERE access_url_id = $access_url_id  
 				ORDER BY lastname,firstname,username";
 		}
-	}	
-	
+	}		
 	$result=api_sql_query($sql,__FILE__,__LINE__);	
-	$Users=api_store_result($result);
-	
-	foreach($Users as $user) {
+	$Users=api_store_result($result);	
+	foreach ($Users as $user) {
 		$sessionUsersList[$user['user_id']] = $user ;
 	}
 } else {
+		$use_extra_fields = false;		
+		if (is_array($extra_field_list)) {
+			if (is_array($new_field_list) && count($new_field_list)>0 ) {			
+				$result_list=array();
+				foreach ($new_field_list as $new_field) {
+					$varname = 'field_'.$new_field['variable'];				
+					if (Usermanager::is_extra_field_available($new_field['variable'])) {
+						if (isset($_POST[$varname]) && $_POST[$varname]!='0') {		
+							$use_extra_fields = true;																	
+							$extra_field_result[]= Usermanager::get_extra_user_data_by_value($new_field['variable'], $_POST[$varname]);
+						}								
+					}
+				}									
+			}
+		}	
+		
+		if ($use_extra_fields) {
+			$final_result = array();
+			if (count($extra_field_result)>1) {
+				for($i=0;$i<count($extra_field_result)-1;$i++) {
+					if (is_array($extra_field_result[$i+1])) {
+						$final_result  = array_intersect($extra_field_result[$i],$extra_field_result[$i+1]);				
+					}
+				}
+			} else {				
+				$final_result = $extra_field_result[0];
+			}
+					
+			$where_filter ='';
+			if ($_configuration['multiple_access_urls']==true) {
+				if (is_array($final_result) && count($final_result)>0) {
+					$where_filter = " AND u.user_id IN  ('".implode("','",$final_result)."') ";
+				} else {
+					//no results
+					$where_filter = " AND u.user_id  = -1"; 
+				}
+			} else {			
+				if (is_array($final_result) && count($final_result)>0) {
+					$where_filter = " WHERE u.user_id IN  ('".implode("','",$final_result)."') ";
+				} else {
+					//no results
+					$where_filter = " WHERE u.user_id  = -1"; 
+				}
+			}		
+		}
 	
-	$sql="SELECT  user_id, lastname, firstname, username, id_session
-			FROM $tbl_user
+	$table_user_field = Database::get_main_table(TABLE_MAIN_USER_FIELD);
+	$table_user_field_values = Database::get_main_table(TABLE_MAIN_USER_FIELD_VALUES);
+		
+	if ($use_extra_fields) {		
+		$sql="SELECT  user_id, lastname, firstname, username, id_session
+			FROM $tbl_user u
 			LEFT JOIN $tbl_session_rel_user
-				ON $tbl_session_rel_user.id_user = $tbl_user.user_id AND id_session = '$id_session' 
+			ON $tbl_session_rel_user.id_user = $tbl_user.user_id AND id_session = '$id_session'
+			$where_filter
 			ORDER BY lastname,firstname,username";
 			
-	global $_configuration;	
+	} else {
+		$sql="SELECT  user_id, lastname, firstname, username, id_session
+			FROM $tbl_user u
+			LEFT JOIN $tbl_session_rel_user
+			ON $tbl_session_rel_user.id_user = $tbl_user.user_id AND id_session = '$id_session' 
+			ORDER BY lastname,firstname,username";
+	}			
+	
 	if ($_configuration['multiple_access_urls']==true) {		
 		$tbl_user_rel_access_url= Database::get_main_table(TABLE_MAIN_ACCESS_URL_REL_USER);	
 		$access_url_id = api_get_current_access_url_id();
@@ -317,11 +395,11 @@ if ($ajax_search) {
 			LEFT JOIN $tbl_session_rel_user
 				ON $tbl_session_rel_user.id_user = u.user_id AND id_session = '$id_session'			 
 			INNER JOIN $tbl_user_rel_access_url url_user ON (url_user.user_id=u.user_id) 
-			WHERE access_url_id = $access_url_id 
+			WHERE access_url_id = $access_url_id  $where_filter
 			ORDER BY lastname,firstname,username";			
 		}
 	}
-
+		
 	$result=api_sql_query($sql,__FILE__,__LINE__);	
 	$Users=api_store_result($result);
 	//var_dump($_REQUEST['id_session']);
@@ -333,7 +411,6 @@ if ($ajax_search) {
 	}
 }
 
-
 if ($add_type == 'multiple') {
 	$link_add_type_unique = '<a href="'.api_get_self().'?id_session='.$id_session.'&add='.$_GET['add'].'&add_type=unique">'.get_lang('SessionAddTypeUnique').'</a>';
 	$link_add_type_multiple = get_lang('SessionAddTypeMultiple');
@@ -351,7 +428,37 @@ if ($add_type == 'multiple') {
 <br><br>
 
 <form name="formulaire" method="post" action="<?php echo api_get_self(); ?>?page=<?php echo $_GET['page'] ?>&id_session=<?php echo $id_session; ?><?php if(!empty($_GET['add'])) echo '&add=true' ; ?>" style="margin:0px;">
-<input type="hidden" name="formSent" value="1" />
+
+<?php
+if ($add_type=='multiple') { 
+	if (is_array($extra_field_list)) {
+		if (is_array($new_field_list) && count($new_field_list)>0 ) {
+			foreach ($new_field_list as $new_field) {
+				echo $new_field['name'];
+				$varname = 'field_'.$new_field['variable'];						
+				echo '&nbsp;<select name="'.$varname.'">';
+				echo '<option value="0">--'.get_lang('Select').'--</option>';	
+				foreach	($new_field['data'] as $option) {
+					$checked='';
+					if (isset($_POST[$varname])) {
+						if ($_POST[$varname]==$option[1]) {
+							$checked = 'selected="true"'; 
+						}
+					}							
+					echo '<option value="'.$option[1].'" '.$checked.'>'.$option[1].'</option>';		
+				}
+				echo '</select>';	
+				echo '&nbsp;&nbsp;';
+			}
+			echo '<input type="button" value="'.get_lang('Filter').'" onclick="validate_filter()" />';
+			echo '<br /><br />';
+		}	
+	}
+}
+?>
+
+<input type="hidden" name="form_sent" value="1" />
+<input type="hidden" name="add_type"  />
 
 <?php
 if(!empty($errorMsg)) {
@@ -360,8 +467,6 @@ if(!empty($errorMsg)) {
 ?>
 
 <table border="0" cellpadding="5" cellspacing="0" width="100%">
-
-
 <!-- Users -->
 <tr>
   <td align="center"><b><?php echo get_lang('UserListInPlatform') ?> :</b>
@@ -380,10 +485,8 @@ if(!empty($errorMsg)) {
 		<div id="ajax_list_users"></div>
 		<?php
   	  } else {
-  	  ?>
-  	  
+  	  ?>  	  
 	  <select id="origin_users" name="nosessionUsersList[]" multiple="multiple" size="15" style="width:300px;">
-
 		<?php
 		foreach($nosessionUsersList as $enreg) {
 		?>
diff --git a/main/admin/user_fields.php b/main/admin/user_fields.php
index d9ff58a332..1b0fa2b065 100644
--- a/main/admin/user_fields.php
+++ b/main/admin/user_fields.php
@@ -57,88 +57,77 @@ if(1)
 	if (isset ($_GET['action']))
 	{
 		$check = Security::check_token('get');
-		if($check)
-		{
-			switch ($_GET['action'])
-			{
+		if($check) {
+			switch ($_GET['action']) {
 				case 'show_message' :
 					Display :: display_normal_message($_GET['message']);
-					break;
+					break;			
 				case 'show_field' :
-					if (api_is_platform_admin() && !empty($_GET['field_id']) && UserManager :: update_extra_field($_GET['field_id'],array('field_visible'=>'1')))
-					{
+					if (api_is_platform_admin() && !empty($_GET['field_id']) && UserManager :: update_extra_field($_GET['field_id'],array('field_visible'=>'1'))) {
 						Display :: display_confirmation_message(get_lang('FieldShown'));
-					}
-					else
-					{
+					} else {
 						Display :: display_error_message(get_lang('CannotShowField'));
 					}
 					break;
 				case 'hide_field' :
-					if (api_is_platform_admin() && !empty($_GET['field_id']) && UserManager :: update_extra_field($_GET['field_id'],array('field_visible'=>'0')))
-					{
+					if (api_is_platform_admin() && !empty($_GET['field_id']) && UserManager :: update_extra_field($_GET['field_id'],array('field_visible'=>'0'))) {
 						Display :: display_confirmation_message(get_lang('FieldHidden'));
-					}
-					else
-					{
+					} else {
 						Display :: display_error_message(get_lang('CannotHideField'));
 					}
 					break;	
 				case 'thaw_field' :
-					if (api_is_platform_admin() && !empty($_GET['field_id']) && UserManager :: update_extra_field($_GET['field_id'],array('field_changeable'=>'1')))
-					{
+					if (api_is_platform_admin() && !empty($_GET['field_id']) && UserManager :: update_extra_field($_GET['field_id'],array('field_changeable'=>'1'))) {
 						Display :: display_confirmation_message(get_lang('FieldMadeChangeable'));
-					}
-					else
-					{
+					} else {
 						Display :: display_error_message(get_lang('CannotMakeFieldChangeable'));
 					}
 					break;	
 				case 'freeze_field' :
-					if (api_is_platform_admin() && !empty($_GET['field_id']) && UserManager :: update_extra_field($_GET['field_id'],array('field_changeable'=>'0')))
-					{
+					if (api_is_platform_admin() && !empty($_GET['field_id']) && UserManager :: update_extra_field($_GET['field_id'],array('field_changeable'=>'0'))) {
 						Display :: display_confirmation_message(get_lang('FieldMadeUnchangeable'));
-					}
-					else
-					{
+					} else {
 						Display :: display_error_message(get_lang('CannotMakeFieldUnchangeable'));
 					}
 					break;
 				case 'moveup' :
-					if (api_is_platform_admin() && !empty($_GET['field_id']))
-					{
-						if (move_user_field('moveup', $_GET['field_id']))
-						{
+					if (api_is_platform_admin() && !empty($_GET['field_id'])) {
+						if (move_user_field('moveup', $_GET['field_id'])) {
 							Display :: display_confirmation_message(get_lang('FieldMovedUp'));
-						}
-						else 
-						{
+						} else {
 							Display :: display_error_message(get_lang('CannotMoveField'));
 						}
 					}
 					break;
 				case 'movedown' :
-					if (api_is_platform_admin() && !empty($_GET['field_id']))
-					{					
-						if (move_user_field('movedown', $_GET['field_id']))
-						{
+					if (api_is_platform_admin() && !empty($_GET['field_id'])) {					
+						if (move_user_field('movedown', $_GET['field_id'])) {
 							Display :: display_confirmation_message(get_lang('FieldMovedDown'));
-						}
-						else 
-						{
+						} else {
 							Display :: display_error_message(get_lang('CannotMoveField'));
 						}					
 					}				
 					break;
+				case 'filter_on' :
+					if (api_is_platform_admin() && !empty($_GET['field_id']) && UserManager :: update_extra_field($_GET['field_id'],array('field_filter'=>'1'))) {
+						Display :: display_confirmation_message(get_lang('FieldShown'));
+					} else {
+						Display :: display_error_message(get_lang('CannotShowField'));
+					}
+					break;
+				case 'filter_off' :
+					if (api_is_platform_admin() && !empty($_GET['field_id']) && UserManager :: update_extra_field($_GET['field_id'],array('field_filter'=>'0'))) {
+						Display :: display_confirmation_message(get_lang('FieldShown'));
+					} else {
+						Display :: display_error_message(get_lang('CannotShowField'));
+					}
+					break;
+							
 				case 'delete':
-					if (api_is_platform_admin() && !empty($_GET['field_id']))
-					{
-						if (delete_user_fields($_GET['field_id']))
-						{
+					if (api_is_platform_admin() && !empty($_GET['field_id'])) {
+						if (delete_user_fields($_GET['field_id'])) {
 							Display :: display_confirmation_message(get_lang('FieldDeleted'));
-						}
-						else 
-						{
+						} else {
 							Display :: display_error_message(get_lang('CannotDeleteField'));
 						}
 					}
@@ -147,13 +136,10 @@ if(1)
 			Security::clear_token();
 		}
 	}
-	if (isset ($_POST['action']))
-	{
+	if (isset ($_POST['action'])) {
 		$check = Security::check_token('get');
-		if($check)
-		{
-			switch ($_POST['action'])
-			{
+		if($check) {
+			switch ($_POST['action']) {
 				default:
 					break;
 			}
@@ -177,11 +163,11 @@ if(1)
 
 	// Create a sortable table with user-data
 	$parameters['sec_token'] = Security::get_token();
-	$column_show = array(1,1,1,1,1,1,1,1,0,0);
-	$column_order = array(1,2,3,4,5,6,7,8,9,10);
+	$column_show  = array(1,1,1,1,1,1,1,1,1,0,0);
+	$column_order = array(1,2,3,4,5,6,7,8,9,10,11);
 	$extra_fields = UserManager::get_extra_fields(0,100,5,'ASC');
+	
 	$number_of_extra_fields = count($extra_fields);
-
  
 	$table = new SortableTableFromArrayConfig($extra_fields, 5, 50, '', $column_show, $column_order, 'ASC');
 	$table->set_additional_parameters($parameters);
@@ -193,11 +179,13 @@ if(1)
 	$table->set_header(5, get_lang('FieldOrder'));
 	$table->set_header(6, get_lang('FieldVisibility'));
 	$table->set_header(7, get_lang('FieldChangeability'));
-	$table->set_header(8, get_lang('Modify'));
+	$table->set_header(8, get_lang('FieldFilter'));	
+	$table->set_header(9, get_lang('Modify'));
 	$table->set_column_filter(5, 'order_filter');
 	$table->set_column_filter(6, 'modify_visibility');
 	$table->set_column_filter(7, 'modify_changeability');
-	$table->set_column_filter(8, 'edit_filter');
+	$table->set_column_filter(8, 'modify_field_filter');
+	$table->set_column_filter(9, 'edit_filter');
 	$table->set_column_filter(2, 'type_filter');
 	$table->display();
 }
@@ -302,6 +290,12 @@ function modify_changeability($changeability,$url_params,$row)
 	return ($changeability?'<a href="'.api_get_self().'?action=freeze_field&field_id='.$row[0].'&sec_token='.$_SESSION['sec_token'].'">'.Display::return_icon('right.gif', get_lang('MakeUnchangeable')).'</a>':'<a href="'.api_get_self().'?action=thaw_field&field_id='.$row[0].'&sec_token='.$_SESSION['sec_token'].'">'.Display::return_icon('wrong.gif', get_lang('MakeChangeable')).'</a>');
 }
 
+function modify_field_filter ($changeability,$url_params,$row)
+{
+	return ($changeability?'<a href="'.api_get_self().'?action=filter_off&field_id='.$row[0].'&sec_token='.$_SESSION['sec_token'].'">'.Display::return_icon('right.gif', get_lang('FilterOff')).'</a>':'' .
+						   '<a href="'.api_get_self().'?action=filter_on&field_id='.$row[0].'&sec_token='.$_SESSION['sec_token'].'">'.Display::return_icon('wrong.gif', get_lang('FilterOn')).'</a>');
+}
+
 function edit_filter($id,$url_params,$row)
 {
 	global $charset;
diff --git a/main/auth/profile.php b/main/auth/profile.php
index 63243f7850..83f36add59 100644
--- a/main/auth/profile.php
+++ b/main/auth/profile.php
@@ -1,4 +1,4 @@
-<?php // $Id: profile.php 18425 2009-02-10 22:29:20Z iflorespaz $
+<?php // $Id: profile.php 18449 2009-02-11 21:16:29Z juliomontoya $
 /* For licensing terms, see /dokeos_license.txt */
 /**
 ==============================================================================
@@ -316,7 +316,7 @@ foreach($extra as $id => $field_details)
 			break;
 		case USER_FIELD_TYPE_RADIO:
 			$group = array();
-			foreach($field_details[8] as $option_id => $option_details)
+			foreach($field_details[9] as $option_id => $option_details)
 			{
 				$options[$option_details[1]] = $option_details[2];
 				$group[] =& HTML_QuickForm::createElement('radio', 'extra_'.$field_details[1], $option_details[1],$option_details[2].'<br />',$option_details[1]);
@@ -326,7 +326,7 @@ foreach($extra as $id => $field_details)
 			break;
 		case USER_FIELD_TYPE_SELECT:
 			$options = array();
-			foreach($field_details[8] as $option_id => $option_details)
+			foreach($field_details[9] as $option_id => $option_details)
 			{
 				$options[$option_details[1]] = $option_details[2];
 			}
@@ -335,7 +335,7 @@ foreach($extra as $id => $field_details)
 			break;
 		case USER_FIELD_TYPE_SELECT_MULTIPLE:
 			$options = array();
-			foreach($field_details[8] as $option_id => $option_details)
+			foreach($field_details[9] as $option_id => $option_details)
 			{
 				$options[$option_details[1]] = $option_details[2];
 			}
@@ -359,7 +359,7 @@ foreach($extra as $id => $field_details)
 			$form -> setDefaults($defaults);
 			break;
 		case USER_FIELD_TYPE_DOUBLE_SELECT:
-			foreach ($field_details[8] as $key=>$element)
+			foreach ($field_details[9] as $key=>$element)
 			{
 				if ($element[2][0] == '*')
 				{
diff --git a/main/inc/lib/usermanager.lib.php b/main/inc/lib/usermanager.lib.php
index 0fb1e995b5..824ece7f41 100644
--- a/main/inc/lib/usermanager.lib.php
+++ b/main/inc/lib/usermanager.lib.php
@@ -1,4 +1,4 @@
-<?php // $Id: usermanager.lib.php 18174 2009-02-02 23:36:04Z iflorespaz $
+<?php // $Id: usermanager.lib.php 18449 2009-02-11 21:16:29Z juliomontoya $
 /*
 ==============================================================================
 	Dokeos - elearning and course management software
@@ -705,18 +705,16 @@ class UserManager
 	 * @param	array	Database columns and their new value
 	 * @return	boolean	true if field updated, false otherwise
 	 */
-	function update_extra_field($fid,$columns)
+	function update_extra_field($fid,$columns) 
 	{
 		//TODO check that values added are values proposed for enumerated field types
-		$t_uf = Database::get_main_table(TABLE_MAIN_USER_FIELD);
-		$fid = Database::escape_string($fid);
+		$t_uf 	= Database::get_main_table(TABLE_MAIN_USER_FIELD);
+		$fid 	= Database::escape_string($fid);
 		$sqluf = "UPDATE $t_uf SET ";
-		$known_fields = array('id','field_variable','field_type','field_display_text','field_default_value','field_order','field_visible','field_changeable');
+		$known_fields = array('id','field_variable','field_type','field_display_text','field_default_value','field_order','field_visible','field_changeable','field_filter');
 		$safecolumns = array(); 
-		foreach($columns as $index => $newval)
-		{
-			if(in_array($index,$known_fields))
-			{			
+		foreach ($columns as $index => $newval) {
+			if (in_array($index,$known_fields)) {			
 				$safecolumns[$index] = Database::escape_string($newval);
 				$sqluf .= $index." = '".$safecolumns[$index]."', ";
 			}
@@ -861,29 +859,25 @@ class UserManager
 	{
 		$fields = array();
 		$t_uf = Database :: get_main_table(TABLE_MAIN_USER_FIELD);
-		$t_ufo = Database :: get_main_table(TABLE_MAIN_USER_FIELD_OPTIONS);
-		$columns = array('id','field_variable','field_type','field_display_text','field_default_value','field_order','tms');
+		$t_ufo = Database :: get_main_table(TABLE_MAIN_USER_FIELD_OPTIONS);		
+		$columns = array('id','field_variable','field_type','field_display_text','field_default_value','field_order','field_filter','tms');
+		
 		$sort_direction = '';
-		if(in_array(strtoupper($direction),array('ASC','DESC')))
-		{
+		if (in_array(strtoupper($direction),array('ASC','DESC'))) {
 			$sort_direction = strtoupper($direction);
 		}
 		$sqlf = "SELECT * FROM $t_uf ";
-		if($all_visibility==false)
-		{
+		if ($all_visibility==false) {
 			$sqlf .= " WHERE field_visible = 1 ";
 		}
 		$sqlf .= " ORDER BY ".$columns[$column]." $sort_direction " ;
-		if($number_of_items != 0)
-		{
+		if ($number_of_items != 0) {
 			$sqlf .= " LIMIT ".Database::escape_string($from).','.Database::escape_string($number_of_items);
-		}
+		}		
+		
 		$resf = api_sql_query($sqlf,__FILE__,__LINE__);
-		if(Database::num_rows($resf)>0)
-		{
-			while($rowf = Database::fetch_array($resf))
-			{
-				
+		if(Database::num_rows($resf)>0) {
+			while($rowf = Database::fetch_array($resf)) {				
 				$fields[$rowf['id']] = array(
 					0=>$rowf['id'],
 					1=>$rowf['field_variable'],
@@ -895,15 +889,15 @@ class UserManager
 					5=>$rowf['field_order'],
 					6=>$rowf['field_visible'],
 					7=>$rowf['field_changeable'],
-					8=>array()
-				);
+					8=>$rowf['field_filter'],
+					9=>array()
+				);			
+				
 				$sqlo = "SELECT * FROM $t_ufo WHERE field_id = ".$rowf['id']." ORDER BY option_order ASC";
 				$reso = api_sql_query($sqlo,__FILE__,__LINE__);
-				if(Database::num_rows($reso)>0)
-				{
-					while($rowo = Database::fetch_array($reso))
-					{
-						$fields[$rowf['id']][8][$rowo['id']] = array(
+				if (Database::num_rows($reso)>0) {
+					while ($rowo = Database::fetch_array($reso)) {
+						$fields[$rowf['id']][9][$rowo['id']] = array(
 							0=>$rowo['id'],
 							1=>$rowo['option_value'],
 							//2=>(empty($rowo['option_display_text'])?'':get_lang($rowo['option_display_text'],'')),
@@ -1181,7 +1175,7 @@ class UserManager
 	
 	/**
 	 * Check if a field is available
-	 * @param	string	the wanted username
+	 * @param	string	the wanted fieldname
 	 * @return	boolean	true if the wanted username is available
 	 */
 	function is_extra_field_available($fieldname)
@@ -1189,7 +1183,7 @@ class UserManager
 		$t_uf = Database :: get_main_table(TABLE_MAIN_USER_FIELD);
 		$sql = "SELECT * FROM $t_uf WHERE field_variable = '".Database::escape_string($fieldname)."'";
 		$res = api_sql_query($sql,__FILE__,__LINE__);
-		return Database::num_rows($res) <= 0;
+		return Database::num_rows($res) > 0;
 	}
 	/**
 	 * Gets user extra fields data
@@ -1315,10 +1309,7 @@ class UserManager
 		}		
 		return $extra_data;
 	}
-	
-	
-	
-	
+		
 	/**
 	 * Get all the extra field information of a certain field (also the options)
 	 *
@@ -1378,6 +1369,49 @@ class UserManager
 	}
 	
 	
+	function get_extra_user_data_by_value($field_variable, $field_value, $all_visibility = true)
+	{
+		$extra_data = array();		
+		$table_user_field = Database::get_main_table(TABLE_MAIN_USER_FIELD);
+		$table_user_field_values = Database::get_main_table(TABLE_MAIN_USER_FIELD_VALUES);
+		$table_user_field_options= Database::get_main_table(TABLE_MAIN_USER_FIELD_OPTIONS);
+		$where='';
+		/*
+		if (is_array($field_variable_array) && is_array($field_value_array)) {
+			if (count($field_variable_array) == count($field_value_array)) {
+				$field_var_count = count($field_variable_array);
+				for ($i = 0; $i<$field_var_count ; $i++) {
+					if ($i!=0 && $i!=$field_var_count){
+						$where.= ' AND ';
+					}					
+					$where.= "field_variable='".Database::escape_string($field_variable_array[$i])."' AND user_field_options.id='".Database::escape_string($field_value_array[$i])."'";	
+				}	
+			}
+				
+		}*/		
+		$where= "field_variable='".Database::escape_string($field_variable)."' AND field_value='".Database::escape_string($field_value)."'";
+		
+		$sql = "SELECT user_id FROM $table_user_field user_field INNER JOIN $table_user_field_values user_field_values
+				ON (user_field.id = user_field_values.field_id)								  
+				WHERE $where";
+
+		if($all_visibility == true) {
+			$sql .= " AND user_field.field_visible = 1 ";
+		} else {
+			$sql .= " AND user_field.field_visible = 0 ";
+		}			
+		$res = api_sql_query($sql,__FILE__,__LINE__);
+		$result_data = array();
+		if (Database::num_rows($res)>0) {
+			while ($row = Database::fetch_array($res)) {
+				$result_data[]=$row['user_id'];
+			}
+		}		
+		return $result_data;
+	}
+	
+	
+	
 	
 	/**
 	 * Gives a list of [session_id-course_code] => [status] for the current user.