public function canPreview()
    {
        $blCan = null;
        if (($sPrevId = \OxidEsales\Eshop\Core\Registry::getConfig()->getRequestParameter('preview')) &&
            ($sAdminSid = \OxidEsales\Eshop\Core\Registry::getUtilsServer()->getOxCookie('admin_sid'))
        ) {
            $sTable = getViewName('oxuser');
            $oDb = \OxidEsales\Eshop\Core\DatabaseProvider::getDb();
            $sQ = "select 1 from $sTable where MD5( CONCAT( " . $oDb->quote($sAdminSid) . ", {$sTable}.oxid, {$sTable}.oxpassword, {$sTable}.oxrights ) ) = " . \OxidEsales\Eshop\Core\DatabaseProvider::getDb()->quote($sPrevId);
            $blCan = (bool) $oDb->getOne($sQ);
        }

        return $blCan;
    }