public function execute()
 {
     $id = waRequest::post('id', null, waRequest::TYPE_INT);
     $before_id = waRequest::post('before_id', null, waRequest::TYPE_INT);
     if (!$id) {
         $this->errors[] = "Unknown stock";
         return;
     }
     $stock_model = new shopStockModel();
     if (!$stock_model->move($id, $before_id)) {
         $this->errors[] = "Error when move";
     }
 }