my %choices = (
        'fs_sub' => 'File Systems',
        'mem_sub' => 'Memory'
);

##</code><code>##

foreach (keys(%choices)) {
           $choice_menu->command(-label => $choices{$_},
                -activebackground => '#CCCCCC',
                -command => \&$_);
}

##</code><code>##

File Systems
Memory
Memory