public function actionAdd()
 {
     $model = new Relation();
     if (($data = Yii::app()->getRequest()->getPost('Relation')) !== null) {
         $model->setAttributes($data);
         if ($model->validate()) {
             if ($model->addRelation()) {
                 $this->send(ERROR_NONE, 'success');
             }
         } else {
             $this->error->capture($model);
         }
     }
     $this->render('add', array('relation' => $model));
 }