<!-- 把下面代码加到<body>区域中-->
<form action="http://www.knowsky.com/bbs/misc.php?sub=register" method="post" name="agree">
欢迎注册网页教学网技术论坛：
条款若干........
<input type="submit" value="请认真查看<服务条款和声明> (15)" name="agreeb">
</form>
<SCRIPT language=javascript>
<!--
var secs = 15;
document.agree.agreeb.disabled=true;
for(i=1;i<=secs;i++) {
window.setTimeout("update(" + i + ")", i * 1000);
}
function update(num) {
if(num == secs) {
document.agree.agreeb.value =" 我 同 意 ";
document.agree.agreeb.disabled=false;
}
else {
printnr = secs-num;
document.agree.agreeb.value = "请认真查看<服务条款和声明> (" + printnr +")";
}
}
//-->
</SCRIPT>