<body>
<div>
<span id="daojishi">10</span>
<input disabled="disabled" type="button" value="注册" id="anniu" />
</div>
</body>
<script type="text/javascript">
window.setTimeout("daojishi()",1000);
//功能:倒计时减1
function daojishi()
{
//找到span
var s = document.getElementById("daojishi");
//判断
if(parseInt(s.innerHTML)<=0)
{
document.getElementById("anniu").removeAttribute("disabled");
}
else
{
//获取内容,减1之后再交给span
s.innerHTML = parseInt(s.innerHTML)-1;
//每隔一秒调一次该方法
window.setTimeout("daojishi()",1000);
}
}
</script>