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

my $w = new MainWindow(-title => 'Demo Tk');
my $pb = $w->ProgressBar(
	-width => 15,
	-length => 100,
	-from => 0,
	-to => 19
)->pack;
$w->Button(-text => 'Push me', -command => [ \&do_me, $w, $pb ])->pack;

MainLoop;
exit;

sub do_me
{
	my $w = shift;
	my $pb = shift;
	for (0..19)
	{
		$pb->value($_);
		$w->update;
		sleep(1)
	}
}