private void submenu_penjualan_Click(object sender, EventArgs e)
{
if (trx == null)
{
trx = new FormTransaksi();
trx.MdiParent = this;
//panggil void form close
trx.FormClosed += new FormClosedEventHandler(trx_FormClosed);
trx.Show();
}
else
{
trx.Activate();
}
}
void trx_FormClosed(object sender, EventArgs e)
{
trx = null;
}