//method to delete a guest from the relevant booking
public void deleteGuest(string passportNumber, Booking booking)
{
booking.GuestArray.Remove(passportNumber); //remove the guest from the booking given
serializer.amendBookingRemovePassport(booking); //use the serializer to amend the booking which the guest is attributed to
serializer.deleteObject(0, "guest", passportNumber); //use the serializer to remove the guest from file
}