#!/usr/bin/perl

use strict;
use Tk;

my $mw = MainWindow->new;

$mw->Button(-text => 'First Button',
            -command => sub { print "You hit the First Button.\n" }
            )->pack;

$mw->Button(-text => 'Second Button',
            -command => \&second_sub,
            )->pack;

$mw->Button(-text => 'QUIT',
            -command => \&exit,
            )->pack;

MainLoop;

sub second_sub
{
    print "The Second Button invokes a Named Subroutine.\n";
    return;
}