public frmCTHDN(frmHDN f, String mahdn)
        {
            InitializeComponent();

            txtMaHDN.Text = mahdn;
            tg            = f;
        }
        private void nhậpHàngToolStripMenuItem_Click(object sender, EventArgs e)
        {
            frmHDN f = new frmHDN(manv);

            adInPanel(panel, f);
        }