private void tipoDeVentaToolStripMenuItem_Click(object sender, EventArgs e)
{
frmDM_TipoVenta o = new frmDM_TipoVenta(null);
o.MdiParent = this;
o.Show();
}
private void btnGoTipoVenta_Click(object sender, EventArgs e)
{
eTIPO_VENTA o = new eTIPO_VENTA();
o.TVE_codigo = this.cmbTipoVenta.SelectedValue != null?this.cmbTipoVenta.SelectedValue.ToString() : "";
frmDM_TipoVenta o2 = new frmDM_TipoVenta(o);
o2.MdiParent = this.MdiParent;
o2.Show();
}