public ActionResult CrearLista(FormCollection collection)
        {
            try
            {
                var model = new Especial();
                TryUpdateModel(model, new string[]
                {
                    "Nombre", "Descripcion", "FechaInicio",
                    "FechaTermino", "Precio", "ProductoProductoId"
                }, collection.ToValueProvider());

                repository.AddEspecial(model);

                return(RedirectToAction("Lista", new { id = model.Producto.ProductoId }));
            }
            catch
            {
                return(View());
            }
        }