protected virtual void OnFormClosed (FormClosedEventArgs e) {
Application.RemoveForm (this);
FormClosedEventHandler eh = (FormClosedEventHandler)(Events[FormClosedEvent]);
if (eh != null)
eh (this, e);
foreach (Form form in disabled_by_showdialog)
{
form.Enabled = true;
}
disabled_by_showdialog.Clear();
if (modal_dialogs.Contains(this))
modal_dialogs.Remove(this);
}