diff --git a/main/exercice/exercice.php b/main/exercice/exercice.php
index f714d02453..31fdb1b656 100755
--- a/main/exercice/exercice.php
+++ b/main/exercice/exercice.php
@@ -546,7 +546,7 @@ if ($show == 'test') {
 }
 
 if ($is_allowedToEdit && $origin != 'learnpath') {
-	if ($_GET['show'] != 'result') {
+	if ($show != 'result') {
 		echo '<a href="exercise_admin.php?' . api_get_cidreq() . '">' . Display :: return_icon('new_exercice.png', get_lang('NewEx'),'','32').'</a>';
 		echo '<a href="question_create.php?' . api_get_cidreq() . '">' . Display :: return_icon('new_question.png', get_lang('AddQ'),'','32').'</a>';
 		echo '<a href="hotpotatoes.php?' . api_get_cidreq() . '">' . Display :: return_icon('import_hotpotatoes.png', get_lang('ImportHotPotatoesQuiz'),'','32').'</a>';
@@ -711,7 +711,7 @@ if ($show == 'test') {
             $myorigin     = (empty ($origin)              ? '' : '&origin=' . $origin);
             $mylpid       = (empty ($learnpath_id)        ? '' : '&learnpath_id=' . $learnpath_id);
             $mylpitemid   = (empty ($learnpath_item_id)   ? '' : '&learnpath_item_id=' . $learnpath_item_id);
-    
+            
             $token = Security::get_token();
             $i=1;
             
@@ -727,7 +727,8 @@ if ($show == 'test') {
             
             $header_list = '';
             foreach($headers as $header) {                
-                $header_list .= Display::tag('th', $header['name'], $header['params']);	
+                $params = isset($header['params'])? $header['params'] : null;
+                $header_list .= Display::tag('th', $header['name'], $params);	
             }
             echo Display::tag('tr', $header_list);
             
@@ -806,7 +807,7 @@ if ($show == 'test') {
                     } else {
                         $title = $row['title'];
                     }
-                    $url = '<a href="exercise_submit.php?'.api_get_cidreq().$myorigin.$mylpid.$myllpitemid.'&exerciseId='.$row['id'].'"><img src="../img/quiz.gif" /> '.$title.' </a>'.$lp_blocked;                    
+                    $url = '<a href="exercise_submit.php?'.api_get_cidreq().$myorigin.$mylpid.$mylpitemid.'&exerciseId='.$row['id'].'"><img src="../img/quiz.gif" /> '.$title.' </a>'.$lp_blocked;                    
                     $item =  Display::tag('td', $url.' '.$session_img);  
                     $exid = $row['id'];
     
@@ -865,12 +866,12 @@ if ($show == 'test') {
                     // if time is actived show link to exercise
                     if ($time_limits) {                 
                         if ($is_actived_time) {
-                            $url =  '<a href="exercise_submit.php?'.api_get_cidreq().$myorigin.$mylpid.$myllpitemid.'&exerciseId='.$row['id'].'">'.$row['title'].'</a>';
+                            $url =  '<a href="exercise_submit.php?'.api_get_cidreq().$myorigin.$mylpid.$mylpitemid.'&exerciseId='.$row['id'].'">'.$row['title'].'</a>';
                         } else {
                             $url = $row['title'];                            
                         }                       
                     } else {
-                        $url = '<a href="exercise_submit.php?'.api_get_cidreq().$myorigin.$mylpid.$myllpitemid.'&exerciseId='.$row['id'].'">'.$row['title'].'</a>';                       
+                        $url = '<a href="exercise_submit.php?'.api_get_cidreq().$myorigin.$mylpid.$mylpitemid.'&exerciseId='.$row['id'].'">'.$row['title'].'</a>';                       
                     }                   
                     
                     //Link of the exercise             
@@ -1007,7 +1008,7 @@ if ($show == 'test') {
     }
     
     $nbrActiveTests = 0;
-    if (is_array($attribute['path'])) {
+    if (isset($attribute['path']) && is_array($attribute['path'])) {
         while (list($key, $path) = each($attribute['path'])) {
             $item = '';
             list ($a, $vis) = each($attribute['visibility']);
diff --git a/main/exercice/exercise.class.php b/main/exercice/exercise.class.php
index 9e4d445e6f..b54bb91947 100755
--- a/main/exercice/exercise.class.php
+++ b/main/exercice/exercise.class.php
@@ -134,8 +134,10 @@ class Exercise {
             //this is needed only is there is no questions
             //
             // @todo not sure were in the code this is used somebody mess with the exercise tool
+            // @todo don't know who add that config and why $_configuration['live_exercise_tracking'] 
             global $_configuration, $questionList;
-            if ($this->type == ONE_PER_PAGE && $_configuration['live_exercise_tracking'] && $_SERVER['REQUEST_METHOD'] != 'POST' && defined('QUESTION_LIST_ALREADY_LOGGED')) {
+            if ($this->type == ONE_PER_PAGE && $_SERVER['REQUEST_METHOD'] != 'POST' && defined('QUESTION_LIST_ALREADY_LOGGED') && 
+                isset($_configuration['live_exercise_tracking']) && $_configuration['live_exercise_tracking']) {
             	//if(empty($_SESSION['questionList']))
             	$this->questionList = $questionList;
             }
@@ -1541,7 +1543,7 @@ class Exercise {
 	    $html =  '<div style="margin-top:-10px;">';	
 	    $confirmation_alert = $this->type == 1? " onclick=\"javascript:if(!confirm('".get_lang("ConfirmYourChoice")."')) return false;\" ":"";	    
 	    $submit_btn = '<button class="next" type="submit" name="submit" name="submit_save" id="submit_save" '.$confirmation_alert.' >';
-		$hotspot_get = $_POST['hotspot'];
+		$hotspot_get = isset($_POST['hotspot'])?Security::remove_XSS($_POST['hotspot']):null;
 				
 	    if ($this->selectFeedbackType() == EXERCISE_FEEDBACK_TYPE_DIRECT && $this->type == ONE_PER_PAGE) {
 	        $submit_btn = '';
diff --git a/main/exercice/question.class.php b/main/exercice/question.class.php
index cea1fd0dd2..5a7de074ac 100755
--- a/main/exercice/question.class.php
+++ b/main/exercice/question.class.php
@@ -82,7 +82,10 @@ abstract class Question
 	}
 
 	public function getIsContent() {
-		$isContent = intval($_REQUEST['isContent']);
+	    $isContent = null;
+	    if (isset($_REQUEST['isContent'])) {
+		    $isContent = intval($_REQUEST['isContent']);
+	    }
 		return $this->isContent = $isContent;
 	}
 
diff --git a/main/exercice/question_list_admin.inc.php b/main/exercice/question_list_admin.inc.php
index e7b1d140ac..1e9724813d 100755
--- a/main/exercice/question_list_admin.inc.php
+++ b/main/exercice/question_list_admin.inc.php
@@ -169,21 +169,19 @@ if ($nbrQuestions) {
     //forces the query to the database
     $my_exercise->read($_GET['exerciseId']);
 	$questionList=$my_exercise->selectQuestionList();    
-    
-	$i=1;
-    
-	if (is_array($questionList)) {
         
-        echo '<div id="question_list">';
-        		
+	if (is_array($questionList)) {      
+	      
+        echo '<div id="question_list">';        		
 		foreach($questionList as $id) {
 			//To avoid warning messages
 			if (!is_numeric($id)) {
 				continue;
 			}	
 			$objQuestionTmp = Question :: read($id);
-            $question_class = get_class($objQuestionTmp);            
-            $label          = $question_class->$explanationLangVar;            
+            $question_class = get_class($objQuestionTmp);
+            //$label          = $question_class->$explanationLangVar;
+            
             
             $edit_link = '<a href="'.api_get_self().'?'.api_get_cidreq().'&type='.$objQuestionTmp->selectType().'&myid=1&editQuestion='.$id.'">'.Display::return_icon('edit.gif',get_lang('Modify')).'</a>';          
             // this variable  $show_quiz_edition comes from admin.php blocks the exercise/quiz modifications
@@ -207,9 +205,9 @@ if ($nbrQuestions) {
                 echo '</div>';
             
                 echo '<div class="question-list-description-block">';
-                    echo '<p>';
-                        //echo $actions;
-                        echo get_lang($question_class.$label);
+                    echo '<p>';                        
+                        //echo get_lang($question_class.$label);
+                        echo get_lang($question_class);
                         echo '<br />';
                         //echo get_lang('Level').': '.$objQuestionTmp->selectLevel();
                         echo '<br />';
@@ -225,16 +223,7 @@ if ($nbrQuestions) {
         echo '</div>';
 	}
 }
-?>
-</table></div>
-<table border="0" align="center" cellpadding="2" cellspacing="2" width="100%">
-<?php
-if(!$i) {
-	?>
-	<tr>
-  	<td><?php echo get_lang('NoQuestion'); ?></td>
-	</tr>
-<?php
-}
-?>
-</table>
\ No newline at end of file
+echo '</table></div>';
+if(!$nbrQuestions) {	
+  	echo Display::display_warning_message(get_lang('NoQuestion'));
+}
\ No newline at end of file
diff --git a/main/inc/header.inc.php b/main/inc/header.inc.php
index fcced3b68d..6c9a6f2936 100755
--- a/main/inc/header.inc.php
+++ b/main/inc/header.inc.php
@@ -7,9 +7,6 @@
  */
 
 /*  HEADERS SECTION */
-/*
- * HTTP HEADER
- */
 
 // Server mode indicator.
 if (api_is_platform_admin()) {
@@ -167,7 +164,7 @@ if (isset($htmlIncHeadXtra) && $htmlIncHeadXtra) {
 include api_get_path(LIBRARY_PATH).'javascript/email_links.lib.js.php';
 
 $favico = '<link rel="shortcut icon" href="'.api_get_path(WEB_PATH).'favicon.ico" type="image/x-icon" />';
-if ($_configuration['multiple_access_urls']) {
+if (isset($_configuration['multiple_access_urls']) && $_configuration['multiple_access_urls']) {
     $access_url_id = api_get_current_access_url_id();
     if ($access_url_id != -1) {
         $url_info = api_get_access_url($access_url_id);
diff --git a/main/inc/lib/database.lib.php b/main/inc/lib/database.lib.php
index f5b6cf7693..4477917169 100755
--- a/main/inc/lib/database.lib.php
+++ b/main/inc/lib/database.lib.php
@@ -1124,7 +1124,7 @@ class Database {
         if (empty($conditions)) {
             return '';
         }
-        $return_value = '';    
+        $return_value = $where_return = '';    
         foreach ($conditions as $type_condition => $condition_data) {       
             if ($condition_data == false) {
                 continue;
diff --git a/main/inc/lib/online.inc.php b/main/inc/lib/online.inc.php
index 4e99101b11..e316faf0dd 100755
--- a/main/inc/lib/online.inc.php
+++ b/main/inc/lib/online.inc.php
@@ -213,7 +213,7 @@ function who_is_online_count($valid, $friends = false) {
 	}
 
 	global $_configuration;
-	if ($_configuration['multiple_access_urls']) {
+	if (isset($_configuration['multiple_access_urls']) && $_configuration['multiple_access_urls']) {
 		$tbl_user_rel_access_url= Database::get_main_table(TABLE_MAIN_ACCESS_URL_REL_USER);
 		$access_url_id = api_get_current_access_url_id();
 		if ($access_url_id != -1) {