private void porFormaDePagoToolStripMenuItem_Click(object sender, EventArgs e)
        {
            frmVentaFormaPago frm = new frmVentaFormaPago();

            frm.MdiParent = this;
            frm.Show();
        }
 public frmVentaFormaPago()
 {
     InitializeComponent();
     frmVentaFormaPago.f1 = this;
 }