protected function GetTransactionStatus($sPayId = null)
    {
        $aParameter = array('PSPID' => $this->GetConfigParameter('user_id'), //required
            'USERID' => $this->GetConfigParameter('api_user_id'), //required
            'PSWD' => $this->GetConfigParameter('pswd'), //required
        );

        if (null !== $sPayId) {
            $aParameter['PAYID'] = $sPayId;
        } else {
            $aParameter = array_merge($aParameter, $this->GetOrderOrPayIdAuthenticationArray());
        }

        $sExternalHandlerURL = $this->GetDirectQueryURL().'?'.str_replace('&amp;', '&', TTools::GetArrayAsURL($aParameter));
        TTools::WriteLogEntry('OGONE DirectLink: called url: '.$sExternalHandlerURL, 4, __FILE__, __LINE__);
        $sResult = file_get_contents($sExternalHandlerURL);
        TTools::WriteLogEntry('OGONE DirectLink: XML response from DirectLink call: '.$sResult, 1, __FILE__, __LINE__);

        if (false !== $sResult) {
            $this->ParseXMLResponse($sResult);
        }

        return $this->PaymentSuccess();
    }