use strict;
use warnings;
use Tk;

# Das mw erzeugen
my $mw = MainWindow->new(-background => 'lightskyblue1');

$mw -> title('Test für pack');
$mw->geometry("200x100");

my $text = "Unpack";
my $button = $mw->Button(-textvariable => \$text,
                         -command => \&doit)  ->pack();

my $label = $mw->Label(-text => "Hallo Welt,\nhallo Universum");
$label->pack(-fill => 'x', -expand => 1);

MainLoop();

sub doit
  {
 	if($text eq "Unpack")
 	  {
 		$label->packForget();
 		$text = "Pack";
 	  }
 	else
 	  {
 		$label->pack(-fill => 'x', -expand => 1);
 		$text = "Unpack";
 	  }
  }