here my changings ...
1. in the file details.php
after your ...
$comment_rank .= "+".$comment_row[$i]['is_good']." ".$comrate_good." ".$comrate_bad." ".$comment_row[$i]['is_bad']."-";
I added this...
$site_template->register_vars("comment_rank", $comment_rank);
Thank you mawenzi, I forgot to add this step.
... I think, you should post your [MOD] Rate Comments in a new thread in Mods & Plugins (Requests & Discussions) ...
... and then we will move this thread to Mods & Plugins (Releases & Support) ...
Am I need to create a new topic?
Also I think will be more interesting if some function will based on comment_rank.
For example:
user rate comment -> comment's author karma +point (or -point)
when comment's author will get karma = 20, he will allowed to download/upload more images
his karma can be again < 20, so it's good motivation for user to be an active member.