private void dataKasirToolStripMenuItem_Click(object sender, EventArgs e)
{
if (kasir == null)
{
kasir = new Kasir();
kasir.MdiParent = this;
kasir.FormClosed += new FormClosedEventHandler(Kasir_Closed);
kasir.Show();
}
else
{
kasir.Activate();
}
}
void Kasir_Closed(object sender, FormClosedEventArgs e)
{
kasir = null;
}