private void btEdit_Click(object sender, EventArgs e)
        {
            int soLuong;
            int idMenu = Convert.ToInt32(cbMenu.SelectedValue.ToString());

            if (checkNumber(tbSoLuong.Text))
            {
                soLuong = Convert.ToInt32(tbSoLuong.Text);
                int         idMenuSelect = Convert.ToInt32(cbMenu.SelectedValue.ToString());
                BillInfoDAL billInfoDAL  = new BillInfoDAL();
                billInfoDAL.editBillInfo(table.Status, idMenuSelect, soLuong);
                loadBill(this.table.Status);
            }
        }