#!/usr/bin/perl -w
use strict;
use Tk;

my &#36counter;
my &#36myvar = "Der Zähler steht momentan auf 0.";
my &#36win = MainWindow->new(-background => "#000000");
&#36win->title("Zählerprogramm");
my &#36text = &#36win->Label(-foreground => "white", -background => "#000000", -textvariable => \&#36myvar);
my &#36button = &#36win->Button(-text => "+", -foreground => "white", -background => "#000088", -command => sub { handler(1) });
my &#36button2 = &#36win->Button(-text => "-", -foreground => "white",  -background => "#000088", -command => sub { handler(2) });
&#36text->pack();
&#36button->pack(-side => "left");
&#36button2->pack(-side => "right");
MainLoop;

sub handler {
    my &#36option = shift;
    &#36option == 1 ? ++&#36counter : --&#36counter;
    &#36myvar = "Der Zähler steht momentan auf &#36counter.";
}