private void toolStripButton2_Click(object sender, EventArgs e)
        {
            var qtht = bdsQTHT.Current as QTHT;

            if (qtht != null)
            {
                var f = new frmQTHTChiTiet(qtht);
                f.ShowDialog();
            }
        }
        private void toolStripButton1_Click(object sender, EventArgs e)
        {
            frmQTHTChiTiet themqtht = new frmQTHTChiTiet();

            themqtht.ShowDialog();
        }