public ActionResult Add(int bookID, string returnURL) { AppUser user = UserManager.Users.FirstOrDefault(x => x.UserName == User.Identity.Name); if (user != null) { if (ShelfRepository.CheckExisting(user.Id, bookID)) { TempData["Message"] = new Message() { Text = "Info! <strong>You have already added this book to your shelf.</strong>", ClassName = "alertMessage info" }; } else { Shelf shelf = new Shelf() { BookID = bookID, UserID = user.Id }; ShelfRepository.AddBookToShelf(shelf); TempData["Message"] = new Message() { Text = "Success! <strong>You have successfully added book to your shelf.</strong>", ClassName = "alertMessage successful" }; } } else { TempData["Message"] = new Message() { Text = "Error! <strong>User is not logged in.</strong>", ClassName = "alertMessage error" }; } return(Redirect(returnURL)); }