public ActionResult InstructorDetail(int id)
        {
            TeachersClient TC = new TeachersClient();

            ViewBag.Teachers = TC.find(id);
            DateTime datejoin = TC.find(id).date_join.Value;

            ViewBag.joinDate = datejoin.ToString("dd/MM/yyyy");
            return(View());
        }
        //Lay thong tin cua giao vien cho trang chi tiet Course
        public void GetTeacher(int id)
        {
            TeachersClient TC = new TeachersClient();

            ViewBag.Teacher = TC.find(id);
        }