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

use Tk;

my $mw = MainWindow -> new;
my $m  = $mw -> Message (-text => "testing, one, two, three...") -> pack;
$mw->Button(-text    => 'Go',
            -command => \&fire)->pack;
MainLoop();

sub fire {
    for my $n (1 .. 10) {
        print "$n\n";
        sleep 1;
    }
    $m -> destroy;
    print "Done\n";
}