Real time changing clock with JavaScript

gistfile1.txt

<script>
    function startTime() {
        var today = new Date();
        var h = today.getHours();
        var m = today.getMinutes();
        var s = today.getSeconds();
        m = checkTime(m);
        s = checkTime(s);
        document.getElementById('time').innerHTML =
            h + ":" + m + ":" + s;
        var t = setTimeout(startTime, 500);
        return h;
    }
    function checkTime(i) {
        if (i <10) {i = "0" + i}
        return i;
    }
</script>

//In HTML 
...
<div id="somid">Some content</div>
<script type="text/javascript">
   oQuickReply.swap('somid');
</script>
...