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

use Tk;
use Tk::Photo;

my $mw    = MainWindow-> new ();
my $icon    = "icon1.bmp";

$mw-> repeat (1000, sub {
    if ($icon eq "icon2.bmp") {
    $icon = "icon1.bmp";
  } else {
    $icon = "icon2.bmp";
  } 
  $mw->idletasks;
  $mw->iconimage($mw->Photo(-file => $icon) ); 
}
);
MainLoop ();