Alright! After about 20 hours of research, I found the answer in a blog by Ryan Pharis (link above). As I was suspecting, it was an easy solution.
Wordpress is using "user friendly URLS". Therefore my path ended up like this: http://www.mysite.com/includes/autosuggest.php?json=true&; The REAL path is this: http://www.mysite.com/wp-content/themes/my_theme/includes/autosuggest.php?json=true&; My script cannot be located in an external .js script, because I need to get the URL from Wordpress. So I did this: <?php $site_url = bloginfo('template_url'); ?> <script type="text/javascript"> var options = { script:"<?php echo $site_url; ?>includes/autosuggest.php? json=true&", Now my script works and I'm a happy camper.
