private void операцииПоГПToolStripMenuItem_Click(object sender, EventArgs e) { if (f18 == null) { f18 = new Form18(); f18.MdiParent = this; f18.FormClosed += new FormClosedEventHandler(f18_FormClosed); f18.Show(); } else { f18.Activate(); } }
void f18_FormClosed(object sender, FormClosedEventArgs e) { f18 = null; }