public function getAddUrlParams()
    {
        $sAddParams = parent::getAddUrlParams();
        $sAddParams .= ($sAddParams ? '&amp;' : '') . "listtype={$this->_sListType}";
        $oConfig = \OxidEsales\Eshop\Core\Registry::getConfig();

        if ($sParam = $oConfig->getRequestParameter('searchparam', true)) {
            $sAddParams .= "&amp;searchparam=" . rawurlencode($sParam);
        }

        if ($sParam = $oConfig->getRequestParameter('searchcnid')) {
            $sAddParams .= "&amp;searchcnid=$sParam";
        }

        if ($sParam = rawurldecode($oConfig->getRequestParameter('searchvendor'))) {
            $sAddParams .= "&amp;searchvendor=$sParam";
        }

        if ($sParam = rawurldecode($oConfig->getRequestParameter('searchmanufacturer'))) {
            $sAddParams .= "&amp;searchmanufacturer=$sParam";
        }

        return $sAddParams;
    }