diff --git a/main/admin/usergroups.php b/main/admin/usergroups.php
index 040a1c4814..f33f31e464 100755
--- a/main/admin/usergroups.php
+++ b/main/admin/usergroups.php
@@ -18,7 +18,7 @@ api_protect_admin_script(true);
 $htmlHeadXtra[] = api_get_jqgrid_js();
 // setting breadcrumbs
 $interbreadcrumb[] = array('url' => 'index.php','name' => get_lang('PlatformAdmin'));
-$action = $_GET['action'];
+$action = isset($_GET['action']) ? $_GET['action'] : null;
 if ($action == 'add') {
     $interbreadcrumb[] = array('url' => 'usergroups.php','name' => get_lang('Classes'));
     $interbreadcrumb[] = array('url' => '#','name' => get_lang('Add'));
@@ -30,7 +30,7 @@ if ($action == 'add') {
 }
 
 // The header.
-Display::display_header($tool_name);
+Display::display_header();
 
 // Tool name
 if (isset($_GET['action']) && $_GET['action'] == 'add') {
diff --git a/main/inc/ajax/model.ajax.php b/main/inc/ajax/model.ajax.php
index b8b2ed6df5..f1952f5573 100644
--- a/main/inc/ajax/model.ajax.php
+++ b/main/inc/ajax/model.ajax.php
@@ -996,6 +996,7 @@ switch ($action) {
         $columns = array('name', 'users', 'actions');
         $options = array('order'=>"name $sord", 'LIMIT'=> "$start , $limit");
         $options['course_id'] = $course_id;
+
         switch ($type) {
             case 'not_registered':
                 $options['where'] = array(" (course_id IS NULL OR course_id != ?) " => $course_id);
@@ -1017,8 +1018,8 @@ switch ($action) {
                     $url  = 'class.php?action=add_class_to_course&id='.$group['id'];
                     $icon = Display::return_icon('add.png', get_lang('Add'));
                 }
-                $group['actions']    = Display::url($icon, $url);
-                $new_result[]        = $group;
+                $group['actions'] = Display::url($icon, $url);
+                $new_result[] = $group;
             }
             $result = $new_result;
         }