protected void gridDanhSach_RowUpdating(object sender, DevExpress.Web.Data.ASPxDataUpdatingEventArgs e)
        {
            string ID           = e.Keys[0].ToString();
            string TenChietKhau = e.NewValues["TenChietKhau"].ToString();
            string TyLe         = e.NewValues["TyLe"].ToString();

            data = new dtChietKhau();
            data.CapNhat(ID, TenChietKhau, TyLe);
            e.Cancel = true;

            gridDanhSach.CancelEdit();
            LoadGrid();
        }