<script>
<!--
var limit="3:00"

if (document.images){
var parselimit=limit.split(":")
parselimit=parselimit[0]*60+parselimit[1]*1
}

function beginrefresh(){
if (!document.images)
return
if (parselimit==1)
window.location.reload()
else{
parselimit-=1
curmin=Math.floor(parselimit/60)
cursec=parselimit%60
if (curmin!=0)
curtime=curmin+" min "+cursec+" sec "
else
curtime=cursec+" sec "
window.status=curtime
setTimeout("beginrefresh()",1000)
}
}

window.onload=beginrefresh
//-->
</script>


加到body中間，這里是3:00為三分鐘，可以自定