public function destroy()
 {
     $this->deleted = true;
     if (!$this->id) {
         return;
     }
     $id = mysql_real_escape_string($this->id);
     $count = PaymentTransaction::count("paymentgateways.id = '{$id}'");
     if ($count > 0) {
         throw new Excpetion('Unable to delete payment gateway, there are transactions that are using it');
     }
     mysql_query("UPDATE `paymentgateways` SET `deleted` = true WHERE `id` = '{$id}' LIMIT 1;");
 }