diff --git a/main/session/add_teachers_to_session.php b/main/session/add_teachers_to_session.php
index bc019a4e7e..928bf2ae02 100644
--- a/main/session/add_teachers_to_session.php
+++ b/main/session/add_teachers_to_session.php
@@ -18,14 +18,9 @@ $interbreadcrumb[] = array('url' => 'session_list.php','name' => get_lang('Sessi
 
 // Setting the name of the tool
 $tool_name = get_lang('EnrollTrainersFromExistingSessions');
-$add_type = 'multiple';
-if (isset($_REQUEST['add_type']) && $_REQUEST['add_type']!='') {
-    $add_type = Security::remove_XSS($_REQUEST['add_type']);
-}
+
 $form_sent  = 0;
 $errorMsg   = '';
-$users = $sessions = array();
-
 $id = intval($_GET['id']);
 
 SessionManager::protectSession($id);
@@ -34,7 +29,8 @@ $htmlResult = null;
 
 if (isset($_POST['form_sent']) && $_POST['form_sent']) {
     $form_sent = $_POST['form_sent'];
-    if ($form_sent == 1) {
+
+    if ($form_sent == 1 && isset($_POST['sessions']) && isset($_POST['courses'])) {
         $sessions = $_POST['sessions'];
         $courses = $_POST['courses'];
 
@@ -56,130 +52,57 @@ foreach ($courseList as $course) {
 Display::display_header($tool_name);
 ?>
 
-<form name="formulaire" method="post" action="<?php echo api_get_self(); ?>" style="margin:0px;" >
+<form name="formulaire" method="post" action="<?php echo api_get_self().'?id='.$id; ?>">
 <?php echo '<legend>'.$tool_name.' </legend>';
 echo $htmlResult;
 echo Display::input('hidden', 'form_sent', '1');
 ?>
-    <table border="0" cellpadding="5" cellspacing="0" width="100%">
-        <tr>
-            <td align="center">
-                <b><?php echo get_lang('Sessions') ?> :</b>
-            </td>
-            <td></td>
-            <td align="center">
-                <b><?php echo get_lang('Courses') ?> :</b>
-            </td>
-        </tr>
-        <tr>
-            <td align="center">
-                <?php
-                 echo Display::select(
-                     'sessions[]',
-                     $sessionList,
-                     '',
-                     array('style'=>'width:360px', 'multiple'=>'multiple','id'=>'sessions', 'size'=>'15px'),
-                     false
-                 );
-                ?>
-            </td>
-            <td align="center">
-            </td>
-            <td align="center">
-                <?php
-                echo Display::select(
-                    'courses[]',
-                    $courseOptions,
-                    '',
-                    array('style'=>'width:360px', 'id'=>'courses', 'size'=>'15px'),
-                    false
-                );
-                ?>
-            </td>
-        </tr>
-        <tr>
-            <td colspan="3" align="center">
-                <br />
-                <?php
-                echo '<button class="btn btn-success" type="submit"" >'.
-                    get_lang('SubscribeTeachersToSession').'</button>';
-                ?>
-            </td>
-        </tr>
-    </table>
+<table border="0" cellpadding="5" cellspacing="0" width="100%">
+    <tr>
+        <td align="center">
+            <b><?php echo get_lang('Sessions') ?> :</b>
+        </td>
+        <td></td>
+        <td align="center">
+            <b><?php echo get_lang('Courses') ?> :</b>
+        </td>
+    </tr>
+    <tr>
+        <td align="center">
+            <?php
+             echo Display::select(
+                 'sessions[]',
+                 $sessionList,
+                 '',
+                 array('style'=>'width:360px', 'multiple'=>'multiple','id'=>'sessions', 'size'=>'15px'),
+                 false
+             );
+            ?>
+        </td>
+        <td align="center">
+        </td>
+        <td align="center">
+            <?php
+            echo Display::select(
+                'courses[]',
+                $courseOptions,
+                '',
+                array('style'=>'width:360px', 'id'=>'courses', 'size'=>'15px'),
+                false
+            );
+            ?>
+        </td>
+    </tr>
+    <tr>
+        <td colspan="3" align="center">
+            <br />
+            <?php
+            echo '<button class="btn btn-success" type="submit">'.
+                get_lang('SubscribeTeachersToSession').'</button>';
+            ?>
+        </td>
+    </tr>
+</table>
 </form>
-<script>
-    function moveItem(origin , destination) {
-        for(var i = 0 ; i<origin.options.length ; i++) {
-            if(origin.options[i].selected) {
-                destination.options[destination.length] = new Option(origin.options[i].text,origin.options[i].value);
-                origin.options[i]=null;
-                i = i-1;
-            }
-        }
-        destination.selectedIndex = -1;
-        sortOptions(destination.options);
-    }
-
-    function sortOptions(options) {
-        newOptions = new Array();
-        for (i = 0 ; i<options.length ; i++)
-            newOptions[i] = options[i];
-
-        newOptions = newOptions.sort(mysort);
-        options.length = 0;
-        for(i = 0 ; i < newOptions.length ; i++)
-            options[i] = newOptions[i];
-    }
-
-    function mysort(a, b){
-        if (a.text.toLowerCase() > b.text.toLowerCase()){
-            return 1;
-        }
-        if (a.text.toLowerCase() < b.text.toLowerCase()){
-            return -1;
-        }
-        return 0;
-    }
-
-    function valide(){
-        var options = document.getElementById('session_in_promotion').options;
-        for (i = 0 ; i<options.length ; i++)
-            options[i].selected = true;
-        document.forms.formulaire.submit();
-    }
-
-    function loadUsersInSelect(select) {
-        var xhr_object = null;
-        if(window.XMLHttpRequest) // Firefox
-            xhr_object = new XMLHttpRequest();
-        else if(window.ActiveXObject) // Internet Explorer
-            xhr_object = new ActiveXObject("Microsoft.XMLHTTP");
-        else  // XMLHttpRequest non supporté par le navigateur
-            alert("Votre navigateur ne supporte pas les objets XMLHTTPRequest...");
-
-        xhr_object.open("POST", "loadUsersInSelect.ajax.php");
-        xhr_object.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
-        nosessionUsers = makepost(document.getElementById('session_not_in_promotion'));
-        sessionUsers = makepost(document.getElementById('session_in_promotion'));
-        nosessionClasses = makepost(document.getElementById('origin_classes'));
-        sessionClasses = makepost(document.getElementById('destination_classes'));
-        xhr_object.send("nosessionusers="+nosessionUsers+"&sessionusers="+sessionUsers+"&nosessionclasses="+nosessionClasses+"&sessionclasses="+sessionClasses);
-
-        xhr_object.onreadystatechange = function() {
-            if(xhr_object.readyState == 4) {
-                document.getElementById('content_source').innerHTML = result = xhr_object.responseText;
-            }
-        }
-    }
-
-    function makepost(select) {
-        var options = select.options;
-        var ret = "";
-        for (i = 0 ; i<options.length ; i++)
-            ret = ret + options[i].value +'::'+options[i].text+";;";
-        return ret;
-    }
-</script>
 <?php
 Display::display_footer();