// GET: Books/Details/5
        public ActionResult Details(int?id)
        {
            if (id == null)
            {
                return(new HttpStatusCodeResult(HttpStatusCode.BadRequest));
            }
            Book book = DAL.FindById(id);

            if (book == null)
            {
                return(HttpNotFound());
            }
            return(View(book));
        }