public ActionResult Video(TemasVideoViewModel viewModel)
        {
            if (ModelState.IsValid)
            {
                db.Entry(viewModel.Tema).State = EntityState.Modified;
                db.SaveChanges();
                return(RedirectToAction("Index", "SubTemas", new { id = viewModel.Tema.TemaId }));
            }

            viewModel.Tema = db.Temas.Find(viewModel.Tema.TemaId);

            return(View(viewModel));
        }
        // GET: Admin/Temas/Video/5
        public ActionResult Video(int id)
        {
            if (id == null)
            {
                return(new HttpStatusCodeResult(HttpStatusCode.BadRequest));
            }
            Tema Tema = db.Temas.Where(a => a.TemaId == id).FirstOrDefault();

            if (Tema == null)
            {
                return(HttpNotFound());
            }


            TemasVideoViewModel viewModel = new TemasVideoViewModel();

            viewModel.Tema = db.Temas.Find(Tema.TemaId);
            viewModel.Tema = Tema;
            return(View(viewModel));
        }