public ActionResult AddToTheatre(AddToTheatre model)
        {
            var theatre = db.Theatres.Find(model.selectedTheatre);
            var play    = db.Plays.Find(model.selectedPlay);

            theatre.Plays.Add(play);
            db.SaveChanges();

            return(RedirectToAction("Index", "Theatres"));
        }
        public ActionResult AddToTheatre(int id)
        {
            var model = new AddToTheatre();

            model.selectedTheatre = id;
            model.Plays           = db.Plays.ToList();
            var theatre = db.Theatres.Find(model.selectedTheatre);

            ViewBag.TheatreName = theatre.Name;

            return(View(model));
        }