<script type="text/javascript">

nowHours=0
nowMins=0
nowSecs=0

function tickingTheTock(){

if(nowSecs>59){
nowSecs=0
nowMins++
}

if(nowMins>59){
nowHours++
nowMins=0
}

showHours=chkTick(nowHours)
showMins=chkTick(nowMins)
showSecs=chkTick(nowSecs)

document.getElementById("timerdiv").innerHTML=showHours+" : "+showMins+" : "+showSecs

nowSecs++
tickTimer=setTimeout("tickingTheTock()",1000)

}

function chkTick(n){
if(n<10){
n="0"+n
}
return n
}

// add onload="tickingTheTock()" to the opening body tag

</script>

<div id="timerdiv"></div>