按钮倒计时结束后才能点击提交
<body OnLoad="change()">
<input type=button id="p" disabled >
<script language="JavaScript">
i = 15
function change()
{
var p = document.getElementById("p");
i -- ;
p.value = " 同意 " + i
if (i == 0)
{
p.value='同意';
p.disabled = false
}
else
{
setTimeout("change()", 1000);
}
}
</script>
</body>
演示: