public HttpResponseMessage PostClient([FromBody] RESERVATION reservation)
        {
            try
            {
                using (TECAirlinesDBEntities entities = new TECAirlinesDBEntities())
                {
                    entities.INSERT_RESERVATION(reservation.TICKET_COUNT, reservation.LUGGAGE_COUNT, reservation.SEATS,
                                                reservation.CHECKIN,
                                                reservation.T_TYPE, reservation.PRICE, reservation.CLIENT_ID, reservation.FLIGHT_ID);
                    entities.SaveChanges();

                    var message = Request.CreateResponse(HttpStatusCode.Created, reservation);
                    message.Headers.Location = new Uri(Request.RequestUri + reservation.RESERVATION_ID.ToString());
                    return(message);
                }
            }
            catch (Exception ex)
            {
                return(Request.CreateErrorResponse(HttpStatusCode.BadRequest, ex));
            }
        }