<script type="text/javascript">
var tick;
function stop() {
clearTimeout(tick);
}
function clock() {
var ut=new Date();
var h,m,s;
var time=" ";
h=ut.getHours();
m=ut.getMinutes();
s=ut.getSeconds();
if(s<=9) s="0"+s;
if(m<=9) m="0"+m;
if(h<=9) h="0"+h;
time+=h+":"+m+":"+s;
document.getElementById('clock').innerHTML=time;
tick=setTimeout("clock()",1000);
}
</script>
<body onload="clock();" onunload="stop();">
<p><span id="clock"></span></p>
