public static Reservation GetReservation(int id)
        {
            if (id >= 0) //existing user
            {
                return(ReservationDao.Find(id));
            }
            else if (id == -1) //new user or no user
            {
                return(new Reservation());
            }

            return(null);
        }
        public static int SaveReservation(int reservationId, int clientId, int userId, string destination, string hotel, int people, string details, int totalPrice, int paid, DateTime deadline, DateTime date)
        {
            if (reservationId >= 0) //existing reservation
            {
                var r = ReservationDao.Find(reservationId);

                r.ClientId         = clientId;
                r.UserId           = userId;
                r.Destination      = destination;
                r.HotelName        = hotel;
                r.PersonCount      = people;
                r.Details          = details;
                r.TotalPrice       = totalPrice;
                r.PaidAmount       = paid;
                r.FinalPaymentDate = deadline;
                r.ReservationDate  = date;

                ReservationDao.Update(r);

                return(r.Id);
            }
            else if (reservationId == -1) //new reservation
            {
                var r = new Reservation();

                r.ClientId         = clientId;
                r.UserId           = userId;
                r.Destination      = destination;
                r.HotelName        = hotel;
                r.PersonCount      = people;
                r.Details          = details;
                r.TotalPrice       = totalPrice;
                r.PaidAmount       = paid;
                r.FinalPaymentDate = deadline;
                r.ReservationDate  = date;

                r = ReservationDao.InsertReservation(r);

                return(r.Id);
            }

            return(-1);
        }