public ActionResult Edit(EditViewModel editViewModel)
        {
            if (editViewModel == null)
            {
                throw new HttpException(400, "Bad Request");
            }

            var roomClass = RoomClassService.FindById(editViewModel.RoomClassId);
            if (roomClass == null)
            {
                throw new HttpException(404, "Not Found");
            }

            if (!ModelState.IsValid)
            {
                return View(editViewModel);
            }

            roomClass.Name = editViewModel.Name;
            roomClass.Description = editViewModel.Description;
            RoomClassService.UpdateRoomClass(roomClass);

            TempData["RoomClassId"] = roomClass.RoomClassId;
            TempData["RoomClassName"] = roomClass.Name;
            TempData["Message"] = RoomClassesMessage.EditSuccess;
            return RedirectToAction("index", "roomclasses");
        }
        public ActionResult Edit(int? id)
        {
            if (id == null)
            {
                throw new HttpException(400, "Bad Request");
            }

            var roomClass = RoomClassService.FindById(id.Value);
            if (roomClass == null)
            {
                throw new HttpException(404, "Not Found");
            }

            var editViewModel = new EditViewModel()
            {
                RoomClassId = roomClass.RoomClassId,
                Name = roomClass.Name,
                Description = roomClass.Description,
            };
            return View(editViewModel);
        }