/**
  * Returns the data model based on the primary key given in the GET variable.
  * If the data model is not found, an HTTP exception will be raised.
  * @param integer the ID of the model to be loaded
  */
 public function loadModel($id)
 {
     $model = Party::model()->findByPk($id);
     if ($model === null) {
         throw new CHttpException(404, 'The requested page does not exist.');
     }
     return $model;
 }