/* * True if it is possible to add a guest to the booking, * otherwise false. * Displays error message windows. */ private bool canAddGuest() { bool canAddGuest = true; if (!mFacade.IsABookingLoaded()) { canAddGuest = false; MessageBox.Show("Please save the booking before adding" + " the guests."); } else if (mFacade.GetCurrentNbGuests() >= 4) { canAddGuest = false; MessageBox.Show("This booking is already full, the" + " maximum number of guests per booking" + " is 4."); } return(canAddGuest); }