[jQuery] [validate] validate form fields with php via ajax

this question is about the jquery validation plugin (http://
bassistance.de/jquery-plugins/jquery-plugin-validation/)
i have some input fields in which users can enter URLs. i wrote a php
script which checks the content of these URLs and returns boolean
values depending of the content. is there a possibility to let the
jquery validation-plugin use this php script to check if the input is
valid?