<html>
<script>
var btn;
var i=5;
var timer;
window.onload=function(){
btn=document.getElementById("btn");
btn.disabled=true;
timer=setInterval("Timer()",500);
}
function Timer(){
btn.value="确定"+i;
i--;
if(i<0){
btn.value="确定";
btn.disabled=false;
clearInterval(timer);
}
}
</script>
<body>
<button id="btn">确定5</button>
</body>
</html>
<script>
var btn;
var i=5;
var timer;
window.onload=function(){
btn=document.getElementById("btn");
btn.disabled=true;
timer=setInterval("Timer()",500);
}
function Timer(){
btn.value="确定"+i;
i--;
if(i<0){
btn.value="确定";
btn.disabled=false;
clearInterval(timer);
}
}
</script>
<body>
<button id="btn">确定5</button>
</body>
</html>
timer=setInterval("Timer()",500);
<!--Timer()是函数名,500是0.5秒-->