private void btnThemMoi_Click(object sender, System.EventArgs e)
        {
            var frm = new FrmDatLichDonKhach();

            frm.ShowDialog();
            LoadData();
        }
        private void gridView1_DoubleClick(object sender, System.EventArgs e)
        {
            var db = gridView1.GetFocusedRow() as DUONGDAI_KHACHHEN;

            if (db != null)
            {
                var frm = new FrmDatLichDonKhach();
                frm.SetModel(db);
                frm.ShowDialog();
                LoadData();
            }
        }