<SCRIPT LANGUAGE="JavaScript">

<!--

var maxtime;

if(window.name==''){

maxtime = 60*60;

}else{

maxtime = window.name;

}

function CountDown(){

if(maxtime>=0){

minutes = Math.floor(maxtime/60);

seconds = Math.floor(maxtime%60);

msg = "距离结束还有"+minutes+"分"+seconds+"秒";

document.all["timer"].innerHTML = msg;

if(maxtime == 5*60) alert('注意，还有5分钟!');

--maxtime;

window.name = maxtime;

}

else{

clearInterval(timer);

alert("时间到，结束!");

}

}

timer = setInterval("CountDown()",1000);

//-->

</SCRIPT>

<div id="timer" style="color:red"></div>