public function actionAjax_Create()
 {
     if (isset($_POST['GradingLevels'])) {
         $model = new GradingLevels();
         //set the submitted values
         $model->attributes = $_POST['GradingLevels'];
         //return the JSON result to provide feedback.
         if ($model->save(false)) {
             echo json_encode(array('success' => true, 'id' => $model->primaryKey));
             exit;
         } else {
             echo json_encode(array('success' => false));
             exit;
         }
     }
 }