for (keys %navi) {
		$navigation .= strong ($_);
		for (keys %{$_}) {
			$navigation .= br (). br (). a ({-href => Adresse}, "Name);
}
}

#!c:/perl/bin/perl.exe
use strict;
use warnings;
use Data::Dumper;
use CGI qw/:all start_ul/;
my %navi = ( "Java" => {
                        "Switch" => ["Switch","switch.htm"],
                        "Bubble" => ["Bubblesort","Bubble.htm"]
                        },
             "Andere" => {
                        "Switch" => ["Switch","switch.htm"],
                        "Bubble" => ["Bubblesort","Bubble.htm"]
                         }
            );
my $navigation = '';
for my $key (sort keys %navi) {
  $navigation .= h4($key) . start_ul . "\n";
  for (sort keys %{$navi{$key}}) {
    $navigation .= a({-href=>$navi{$key}{$_}[1],-alt=>$navi{$key}{$_}[0]},$_) . "\n";
  }
  $navigation .= end_ul . "\n";
}
print $navigation;
_ _ END _ _
<h4>Andere</h4><ul>
<a href="Bubble.htm" alt="Bubblesort">Bubble</a>
<a href="switch.htm" alt="Switch">Switch</a>
</ul>
<h4>Java</h4><ul>
<a href="Bubble.htm" alt="Bubblesort">Bubble</a>
<a href="switch.htm" alt="Switch">Switch</a>
</ul>

#!/usr/bin/perl
use strict;
use warnings;
use diagnostics;
use Data::Dumper;

my %navi = (
             "Java" => {
                        "Switch"  => ["Switch","switch.htm"],
                        "Bubble"  => ["Bubblesort","Bubble.htm"],
                       },
             "Dings" => {
                        "Urgs"    => ["Urgelurgs","uuuuuurgllll.htm"],
                        "Gnubbel" => ["Gubblesort","Gnubbel.htm"],
                       },
            );

for my $key (sort keys %navi) {
    print "Key '$key'\n";
    for my $innerkey (sort keys %{$navi{$key}}) {
        print "\tInner Key: '$innerkey'\n";
        for my $value (@{$navi{$key}{$innerkey}}) {
            print "\t\t\tWert = '$value'\n";
        }
    }
}

Key 'Dings'
	Inner Key: 'Gnubbel'
			Wert = 'Gubblesort'
			Wert = 'Gnubbel.htm'
	Inner Key: 'Urgs'
			Wert = 'Urgelurgs'
			Wert = 'uuuuuurgllll.htm'
Key 'Java'
	Inner Key: 'Bubble'
			Wert = 'Bubblesort'
			Wert = 'Bubble.htm'
	Inner Key: 'Switch'
			Wert = 'Switch'
			Wert = 'switch.htm'