<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
<title></title>
<script type="text/javascript">
var time = 10;//指定要过多长时间
function tranform()
{
var btnagree = window.document.getElementById("IDagree");
if (time > 0)
{//在disabled的情况下继续操作控件，让他显示倒计时
btnagree.value = "同意(" + time + "s后继续)";
time--;
}
else {
btnagree.value = "同意";
//够时间的情况下，要把控件的可用性打开
btnagree.disabled = false;//清除时间循环
clearInterval("timeID");
}
}
var timeID = setInterval("tranform()", 1000);
</script>
</head>
<body onload="tranform()">//开始让控件不可用
<input id="IDagree" type="button" value="同意" disabled="disabled" />
</body>
</html>
