public function execute()
 {
     $code = waRequest::post('code', '', waRequest::TYPE_STRING_TRIM);
     if (!$code) {
         $this->errors[] = _w("Unknown currency");
         return;
     }
     $currency_model = new shopCurrencyModel();
     if (!$currency_model->setPrimaryCurrency($code, (bool) waRequest::post('convert'))) {
         $this->errors[] = _w("Error when change");
         return;
     }
 }