Specify AJAX.PHP location

[Exitilus]

Been working on trying to resolve a issue with a mod. I've been working with the developer but the problem is trying to find a way to specify the exact URL to ajax.php or the exact path.

PHP Code:

ajax_mood.send(\'ajax.php\', \'do=insertmood&mood=\' + PHP.urlencode(mood)); 


The way I have my forums setup it is forums.my-domain.com.

The problem lies for my Main Page (VB Advanced) and my gallery which are located at www.my-domain.com/ and gallery.my-domain.com. Because there is no exact path to where ajax.php

I've tried adding the exact root path to ajax.php and URL but neither work O.o Has to be a way to define this...