use Tk; my $mw = MainWindow->new ; my ($m,$t); $mw->geometry("100x100"); $mw->Checkbutton(-text => 'Main',-variable=>\$m)->pack(-side => 'left'); $mw->Button(-text => 'popup', -command => sub {my $t = $mw->Toplevel();$t->geometry("50x50");$t->Checkbutton(-text => 'Top',-variable => \$t)->pack(-side => 'left')})->pack(); MainLoop;