#! /usr/bin/perl
use warnings;
use strict;

use Tk;

my $mw	= MainWindow->new();

createWindowandWait();

print "fertig!\n";

Tk::MainLoop();

sub createWindowandWait{
	my $window	= $mw->Toplevel();

	my $ok	= undef;
	$window->Button(
		-text => 'fertig!',
		-command	=> sub{$ok = 1;}
	)->pack();

	$window->focusForce();

	# warte solange bis variable '$ok' den wert true hat:
	$window->waitVariable(\$ok);
}