public function execute()
 {
     $item = waRequest::post('item', '', waRequest::TYPE_STRING_TRIM);
     $before = waRequest::post('before', null, waRequest::TYPE_STRING_TRIM);
     if (!$item) {
         $this->errors[] = _w("Error when move");
         return;
     }
     $currency_model = new shopCurrencyModel();
     if (!$currency_model->move($item, $before)) {
         $this->errors[] = _w("Error when move");
         return;
     }
 }