public function markAsReserved()
    {
        //saving oxreserved field
        $sVoucherID = $this->oxvouchers__oxid->value;

        if ($sVoucherID) {
            $oDb = \OxidEsales\Eshop\Core\DatabaseProvider::getDb();
            $sQ = "update oxvouchers set oxreserved = " . time() . " where oxid = " . $oDb->quote($sVoucherID);
            $oDb->Execute($sQ);
        }
    }