my $comm_tree = Tree::DAG_Node->new;	#create the root node
$comm_tree->name('CommentRoot');

my %noderef;	#hash of node references, with PID as keys
$noderef{0} = \$comm_tree; #replies to the story have PID==0

##</code><code>##

while ( my $hashref = $query->fetchrow_hashref() ) {
    my $tmpref  = $noderef{ $$hashref{pid} }; 
#reference to the parent node
    my $cid = $$hashref{cid}; 		#CID will be used several times
    my $nodeone = Tree::DAG_Node->new(
        {
            name   => $cid, #CID as node name
            mother => $$tmpref,				#mother is the parent
        }
    );
    $noderef{ $cid }      = \$nodeone; #add this node ref to the hash
    $comm_hashref{ $cid } = $hashref; 
}
##</code><code>##

$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);