public ActionResult Create([Bind(Include = "Id,OrderDate,ReceptionDate,ReturnDate,UserId,BookId")] Order order, FormCollection form) { if (ModelState.IsValid) { try { var DDLValue = Int32.Parse(Request.Form["BookId"]); var availability = _bookRepo.Availability(DDLValue); if (availability == "No") { throw new Exception(); } else { order.UserId = User.Identity.GetUserId(); order.OrderDate = System.DateTime.Now.Date; DateTime date = order.OrderDate; order.ReceptionDate = date.AddDays(2); order.ReturnDate = date.AddDays(30); _repo.AddOrder(order); _repo.SaveChanges(); _bookRepo.ChangeAvailability(order.BookId, "No"); _bookRepo.SaveChanges(); } } catch { ViewBag.Error = true; return(RedirectToAction("Create", new { error = true })); } //ViewBag.Error = false; ViewBag.BookId = new SelectList(_context.Book, "Id", "Title", order.BookId); } return(RedirectToAction("MyOrder")); }