public ActionResult EditProduct(int ID, string name, int?price, int?categoryID, int?salary)
        {
            bool res;

            using (DBAgent.DBAgent agent = new DBAgent.DBAgent())
            {
                res = agent.EditProduct(ID, name, price, categoryID, salary);
            }
            if (res)
            {
                return(Redirect("/Home/Index"));
            }
            else
            {
                return(View("~/Views/Shared/Error.cshtml"));
            }
        }