public ActionResult Block(bool confirm, int idKH)
        {
            if (Session["TaiKhoan"] != null)
            {
                var tk = Session["TaiKhoan"] as KhachHang;


                if (tk.LoaiTK == "Khách Hàng")
                {
                    return(View("../Home/Index"));
                }
                else
                {
                    if (confirm == true)
                    {
                        KhachHangDAO dao = new KhachHangDAO();
                        dao.Block(idKH, tk.MaKH);
                        if (Session["UpdateKH"] != null)
                        {
                            var admin = Session["UpdateKH"] as KhachHang;
                            if (admin.MaKH == idKH)
                            {
                                Session["UpdateKH"] = null;
                            }
                        }
                        Session["ListKH"]      = dao.GetList();
                        Session["ListKHBlock"] = dao.GetListBlock();
                    }
                    return(View("Index"));
                }
            }
            else
            {
                return(View("../DangNhap/Index"));
            }
        }