[jQuery] Autocomplete - Problem accessing php file

[spstieng]

Hi, I have the following script in my index.php file:

  <script type="text/javascript">
        var options = {
                script:"get_labels.php?json=true&",
                varname:"input",
                minchars: 2,
                delay: 200,
                json:true,
                shownoresults:false,
                maxresults:15,
                timeout: 5000
        };
        var autocomplete_json = new bsn.AutoSuggest('labelinput', options);
  </script>

This works fine as long as get_labels.php is located in the same
directory as index.php (root dir).
If I move the script to a folder called 'includes' and use the
following line: script:"includes/get_labels.php?json=true&", it
doesn't work.

I've tried different variations:
includes/get_labels.php?json=true&
/includes/get_labels.php?json=true&
../includes/get_labels.php?json=true&

What am I missing here?

Here's the plugin I'm using:
http://www.brandspankingnew.net/archive/2007/02/ajax_auto_suggest_v2.html