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

my $mw = MainWindow->new;

my $but; # declare before so you can use it in the callback

$but = $mw->Button(-text => "Hello World",

## This callback works (text is changed) under Win95, Win98 (5.6.1)
#
#  -command => [sub { my $b = $_[0],  #notice comma
#      $b->configure(-text => "Hello Stranger");
#   }, $b]);

#This callback works under Win95, Win98 (5.6.1) and Linux (5.6.0)
-command=>[\&change, $but]);

$but->pack;
MainLoop;


sub change {
my $but = $_[0], #notice comma
$but->configure(-text=>"Hello Stranger", -bg => 'pink');
}