public ActionResult Edit(int? id)
{
if (id == null)
{
return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
}
Book book = db.Books.Find(id);
if (book == null)
{
return HttpNotFound();
}
ViewBag.CategoriesID = new SelectList(db.Categories, "ID", "Name", book.CategoriesID);
return View(book);
}