use Tk;
use Tk::ProgressBar;

my $mw = MainWindow->new(-title => 'ProgressBar example');

$progress = $mw->ProgressBar(
			-width => 30,
			-from => 0,
			-to => 100,
			-blocks => 50,
			-colors => [0, 'green', 50, 'yellow', 80, 'red'],
			-variable => \$percent_done
			)->pack(-fill =>'x');
		
$mw->Button(-text =>'Go', command => sub {
					for ($i=0; $i<1000;$i++) {
						$percent_done = $i/10;
						print "$i\n";
						$mw->update;
						}
					})->pack(-side =>'bottom');
					
MainLoop;