use strict;
use warnings;
use Tk;

my $lang = 0;
my $mw                  = Tk::MainWindow->new(-title=>"language support");
$mw->geometry("100x100");

#menubar
my $menubar             = $mw->Menu(-relief => 'flat');
$mw->configure(-menu => $menubar);
my @menulanguages       =("sprache","language");
my $menu_lang           = $menubar->cascade(-label => "$menulanguages[$lang]");
my $german_radio_menu   = $menu_lang->radiobutton(-label=>"deutsch", -variable=>\$lang, -value=>0, -command=>\&update_mw);
my $english_radio_menu  = $menu_lang->radiobutton(-label=>"english", -variable=>\$lang, -value=>1, -command=>\&update_mw);

#button
my @buttonlanguages =("Klick mich","Click me");
my $buttonlabel         = $buttonlanguages[$lang];
my $mybutton            = $mw->Button(-textvariable=>\$buttonlabel)->pack();

Tk::MainLoop();


sub update_mw
{
        $menu_lang->configure(-label => "$menulanguages[$lang]");
        $buttonlabel    = $buttonlanguages[$lang];
}