private void btn_Click(object sender, EventArgs e) { Button btn = sender as Button; tinhTrang = btn.Tag.ToString(); lbMaBan.Text = btn.Text; lbMaHD.Text = dbHoaDon.MaHDChuaTT(btn.Text); dgvGoiMon.DataSource = dbHoaDon.LayDSGoiMon(btn.Text); dgvGoiMon.CurrentCell = null; }