/**
  * Book consultation appointment, was confirmed
  */
 public function bookconfirmed()
 {
     global $ilUser;
     $entry = (int) $_REQUEST['app_id'];
     $user = (int) $_REQUEST['bkid'];
     $form = $this->initFormConfirmBooking();
     if ($form->checkInput()) {
         // check if appointment is bookable
         include_once './Services/Calendar/classes/class.ilCalendarEntry.php';
         $cal_entry = new ilCalendarEntry($entry);
         include_once './Services/Booking/classes/class.ilBookingEntry.php';
         $booking = new ilBookingEntry($cal_entry->getContextId());
         if (!$booking->isAppointmentBookableForUser($entry, $GLOBALS['ilUser']->getId())) {
             ilUtil::sendFailure($this->lng->txt('cal_booking_failed_info'), true);
             $this->ctrl->returnToParent($this);
         }
         include_once './Services/Calendar/classes/ConsultationHours/class.ilConsultationHourUtils.php';
         ilConsultationHourUtils::bookAppointment($ilUser->getId(), $entry);
         include_once './Services/Booking/classes/class.ilBookingEntry.php';
         ilBookingEntry::writeBookingMessage($entry, $ilUser->getId(), $form->getInput('comment'));
     }
     ilUtil::sendSuccess($this->lng->txt('cal_booking_confirmed'), true);
     $this->ctrl->returnToParent($this);
 }