protected function PostInsertHook()
    {
        parent::PostInsertHook();
        // we need to add an order number to the order... since generation of this number may differ
        // from shop to shop, we have added the method to fetch a new order number to the shop class
        $oShop = TdbShop::GetInstance();
        $iOrderNumber = $oShop->GetNextFreeOrderNumber();
        $aData = $this->sqlData;
        $aData['ordernumber'] = $iOrderNumber;
        $this->LoadFromRow($aData);
        $this->Save();
    }