4.) Die einzelnen Untermenüs definieren:
    my $menu_datei = $menu
        ->Menu(-menuitems => [
                              [
                               'command'    => 'Datei neu',
                               -command     => \&datei_neu,
                               -accelerator => 'Ctrl-N',
                               -underline   => 6,
                              ],
                              ..........
                              '-',
                              [
                               'command'    => 'Beenden',
                               -command     => \&tk_ende,
                               -accelerator => 'Ctrl-B',
                               -underline   => 0,
                              ],
                            ],
              );
•5.) Untermenü in Menubar eintragen:
    $menu->entryconfigure('Datei', -menu => $menu_datei);
•
•6.) Bindungen zum Aufruf des Menüs erzeugen:
    $mw->bind('<Alt-d>', sub {$menu->postcascade('Datei');});
    $mw->bind('<Alt-b>', sub {$menu->postcascade('Bearbeiten');});
    $mw->bind('<Alt-h>', sub {$menu->postcascade('Hilfe');});