#!/usr/bin/perl

use strict;
use warnings;

use Tk;
my $mw = MainWindow->new;
my $button = $mw->Button(
    -text => "Hello World!",
    -command => sub{exit}
);
$button->configure(-width =>30);
$button->pack;

$mw->geometry("+100+50"); # +X co-ord +Y co-ord

MainLoop;