private void visitorsToolStripMenuItem_Click(object sender, EventArgs e) { if (visitors == null) { visitors = new frmVisitorsRegistration(); visitors.MdiParent = this; visitors.FormClosed += new FormClosedEventHandler(visitors_FormClosed); visitors.Show(); } else { visitors.Activate(); visitors.WindowState = FormWindowState.Normal; } }
void visitors_FormClosed(object sender, FormClosedEventArgs e) { visitors = null; }