private void операцииПоЦехуToolStripMenuItem_Click(object sender, EventArgs e) { if (f17 == null) { f17 = new Form17(); f17.MdiParent = this; f17.FormClosed += new FormClosedEventHandler(f17_FormClosed); f17.Show(); } else { f17.Activate(); } }
void f17_FormClosed(object sender, FormClosedEventArgs e) { f17 = null; }