protected function save($type)
 {
     $value = waRequest::post($type);
     $product = new shopProduct($this->product_id);
     $product->save(array($type => $value));
     if ($value != 2) {
         $related_model = new shopProductRelatedModel();
         $related_model->deleteByField(array('product_id' => $this->product_id, 'type' => $type));
     }
 }