#!/usr/local/bin/perl -w
use strict;
use Tk qw(MainLoop *widget);
use Carp;

my $mw = MainWindow->new;

$mw->Button(-text => 'Button_1', -command => \&callback)->pack;
my $w = $mw->Button(-text => 'Button_2', -command => \&callback)->pack;

$mw->Button(-text => 'Quit', -command => [destroy => $mw])->pack;

$w->after(1000,\&callback);

MainLoop;

sub callback
{
 print $widget->PathName,"\n";
 my $w = $Tk::widget;
 if (defined $w)
  {
   print "Callback for ",$w->cget('-text'),"\n";
  }
 else
  {
   carp "No widget!";
  }
}