// added to bottom of html file
<script>
    var secondsDelay = 5;

    setInterval(function() {
        reloadQueueListing();
    }, secondsDelay * 1000);

    function reloadQueueListing() {
        var xmlhttp;
        xmlhttp = new XMLHttpRequest();
        xmlhttp.onreadystatechange = function() {
            if(xmlhttp.readyState === 4 && xmlhttp.status === 200) {
                document.getElementById("sidebar-left").innerHTML = xmlhttp.responseText;
            }
        };
        xmlhttp.open("GET", "/rest.queues/queueListing?courseId=21", true);
        xmlhttp.send();
    }
</script>