$comm_tree->walk_down(
    {
        callback => sub {
            my $node = shift;
            my $tmp  = $comm_hashref{ $node->name };
            $$tmp{level} = $_[0]->{_depth};	#add a level key for html indentation
            push @comm_loop, $tmp unless ($node->name eq 'CommentRoot'); #for the HTML::Template loop
        },
        _depth   => 0,
        treename => 'CommentRoot'
    }
);
$template->param(comment_loop => \@comm_loop);