500 (Internal Server Error) – admin-ajax.php

Hi,

I get the below error when trying to fill out my lightbox form on my site here – http://www.meandmymates.com/

POST http://www.meandmymates.com/wp-admin/admin-ajax.php 500 (Internal Server Error)

I filled out the form to confirm my username on your google docs page

Thanks