#!/usr/bin/perl -w
use strict;
use Tk;

my $mw = MainWindow->new(-title=>"Foo!");
my $f  = $mw->Frame(-width=>400, -height=>400)->pack;
print "Tk is $Tk::VERSION; Window id is ",$f->winfo('id'),"\n";
my $child = $mw->Toplevel(-title=>"Bar!",-use=>$f->winfo('id'));
$child->Label(-text=>"Bar!")->pack;
MainLoop;