/**
  * Checks whether a certain user already is registered for this seminar.
  *
  * This method must not be called when no front-end user is logged in!
  *
  * @param tx_seminars_seminar $seminar a seminar for which we'll check if it is possible to register
  *
  * @return string empty string if everything is OK, else a localized error message
  */
 public function isUserRegisteredMessage(tx_seminars_seminar $seminar)
 {
     return $seminar->isUserRegisteredMessage($this->getFeUserUid());
 }
 /**
  * Checks whether a certain user already is registered for this seminar.
  *
  * This method must not be called when no front-end user is logged in!
  *
  * @param tx_seminars_seminar $seminar a seminar for which we'll check if it is possible to register
  *
  * @return string empty string if everything is OK, else a localized error message
  */
 public function isUserRegisteredMessage(tx_seminars_seminar $seminar)
 {
     return $seminar->isUserRegisteredMessage($this->getLoggedInFrontEndUserUid());
 }