Each value in the hash is a hash reference, so you need to dereference the hash reference, then just treat it like a regular hash. Take a look at perlref. Here's some code: 
for my $key1 (sort keys %myhash) {
    print $key1, "\n";
    for my $key2 (sort keys %{$myhash{$key1}}) {
        print "\t", $key2, " => ", $myhash{$key1}{$key2}, "\n";
    }
}

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If you just want to see what a data structure contains, use Data::Dumper: 
use Data::Dumper;
print Dumper \%myhash;

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In reply to Re: Traversing a double hash by btrott
in thread Traversing a double hash by zebroz

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