Html – how to use jquery or ajax to refresh a div at 10 second intervals

Any help at all is appreciated here folks. I'm building a web app in php and I'm using the Yii MVC framework which has a lot of built in tools. Just as the title says, i need to refresh a div every 10 seconds. At the moment I have this ajax function

<script type="text/javascript">
    function ajaxFunction(){
    var ajaxRequest;  

    try{
        // Opera 8.0+, Firefox, Safari
        ajaxRequest = new XMLHttpRequest();
    } catch (e){
        // Internet Explorer Browsers
        try{
            ajaxRequest = new ActiveXObject("Msxml2.XMLHTTP");
        } catch (e) {
            try{
                ajaxRequest = new ActiveXObject("Microsoft.XMLHTTP");
            } catch (e){
                // Something went wrong
                alert("Your browser broke!");
                return false;
            }
        }
    }
    // Create a function that will receive data sent from the server
    ajaxRequest.onreadystatechange = function(){
                var list = document.getElementById('logged_in_users_list');
        if(ajaxRequest.readyState == 4){
            list.innerHTML = ajaxRequest.responseText;
                        setTimeout('ajaxFunction()',10000);
        }
    }
    ajaxRequest.open("GET", "protected/controllers/room/openRoom", true);
    ajaxRequest.send(null);
}
</script>


<script type="text/javascript">
            setInterval(function() {ajaxFunction();}, 5000);
</script>

For those of you who are unfamiliar with Yii it stores most of your php files in a folder called protected. Well it is just that, the ajaxRequest.open line of code above is requesting that url which is stored inside the protected folder, so I keep getting an access forbidden 403 error. Any ideas how I could implement something different with jquery or get round this access problem?