private void btnFactura_Click(object sender, EventArgs e)
{
FrmFactura MiFactura = new FrmFactura();
MiFactura.MdiParent = this;
MiFactura.Show();
}
private void facturasToolStripMenuItem_Click(object sender, EventArgs e)
{
FrmFactura frm = new FrmFactura();
frm.MdiParent = this;
frm.Show();
}