public ActionResult Edit(Slide slide)
 {
     if (ModelState.IsValid)
     {
         db.Entry(slide).State = EntityState.Modified;
         db.SaveChanges();
         return RedirectToAction("Index");
     }
     return View(slide);
 }
        public ActionResult Create(Slide slide)
        {
            if (ModelState.IsValid)
            {
                db.Slides.Add(slide);
                db.SaveChanges();
                return RedirectToAction("Index");
            }

            return View(slide);
        }