Ajax Controller

At the beginning ot the head section of your HTML template you may place the following JavaScript:

Code:

<script type="text/javascript">
    //<![CDATA[
        var site_url = '<?php echo site_url(); ?>';
        // ... and so forth.
    //]]>
    </script>

The variable site_url will be available to the other JavaScripts within the page then, including your AJAX calls.