public String removeUser(Long id) {
   userToRemove = registrationDao.getEntityManager().find(User.class, id);
   registrationDao.remove(userToRemove);
   MessageService.displayFacesMessageInfo(
       "registration_properties", "REGISTRATION_REMOVED_SUMMARY", "REGISTRATION_REMOVED_DETAIL");
   allUsersByCreationDate = registrationDao.findAllUsersByRegistrationDate();
   userToRemove = null;
   return REMOVE_PATH;
 }
 public String prepareUpdateUser(Long id) {
   userListToUpdate = new ArrayList<User>();
   userToUpdate = registrationDao.getEntityManager().find(User.class, id);
   userName = userToUpdate.getUserName();
   firstName = userToUpdate.getFirstName();
   lastName = userToUpdate.getLastName();
   email = userToUpdate.getEmail();
   prepareUpdatedRolePickup();
   prepareUpdatedGroupPickup();
   userListToUpdate.add(userToUpdate);
   allUsersByCreationDate = registrationDao.findAllUsersByRegistrationDate();
   sortPickup();
   return UPDATE_PATH;
 }