public ActionResult Edit(KHOATHI sub)
        {
            bool kq = false;

            if (ModelState.IsValid)
            {
                var dao = new KHOATHIDAO();

                if (dao.UpdateKHOATHI(sub))
                {
                    kq = true;
                }
                else
                {
                    kq = false;
                }
            }

            return(Json(kq, JsonRequestBehavior.AllowGet));
        }