use strict;
use warnings;

my $pardir;

if (exists $ENV{PAR_PROGNAME}){
  # running via PAR/pp
  $pardir = $ENV{PAR_TEMP};
}

use Tk;
use Tk::PNG;
my $png = 'myicon.png';

if ( $pardir ){
  $png = $pardir . '/inc/' . $png; 
}

my $mw = Tk::MainWindow->new();
my $icon = $mw->Photo(-file=> $png);
my $btn = $mw->Button(
  -image => $icon,
);
$btn->pack();
$mw->MainLoop();