public ActionResult Crear(FormCollection collection)
        {
            if (ModelState.IsValid)
            {
                var model = new Producto();
                TryUpdateModel(model, new string[]
                {
                    "Nombre", "Descripcion", "ImagePath",
                    "Visible", "Precio"
                }, collection.ToValueProvider());

                repository.AddProducto(model);

                return(RedirectToAction("Index"));
            }
            else
            {
                // Error
                ModelState.AddModelError("", "Error goes here");
            }

            return(View());
        }