public ActionResult Details(string category, int id, string format = null)
        {
            var repo = new ProductRepository();
            var product = repo.Find(p => p.Id == id);

            if (product.Categories.Any(c => c.Name == category))
            {
                if (format == "json")
                {
                    return Json(product, JsonRequestBehavior.AllowGet);
                }

                return View(product);
            }

            return HttpNotFound();
        }
        public ActionResult ShowCategory(string category)
        {
            var repo = new ProductRepository();

            return View(repo.GetByCategory(category));
        }
        public ActionResult Index()
        {
            var repo = new ProductRepository();

            return View(repo.All());
        }