<html>
<body>
<input?type="text"?id="clock"?size="30"?/>
<span?id?=?"status"?/>
<script?language=javascript>
var?sec?=?5;
var?int=setInterval("clock()",1000)
function?clock()
{document.getElementById("clock").value?=?"倒計時："+sec;
if(sec?==?0){clearInterval(int);
document.getElementById("status").innerHTML?=?"GAME?OVER";?
}
else{
sec?=?sec-1;}
}</script>
</body>
</html>