/**
  * check if user is registered
  *
  * @access privat
  */
 function _auth()
 {
     if ($this->B->auth->is_user !== FALSE) {
         return TRUE;
     } else {
         $query = base64_encode(commonUtil::getQueryString());
         @header('Location: ' . SF_BASE_LOCATION . '/index.php?tpl=login&ret=' . $query);
         exit;
     }
 }