<html>
<head>
<script type="text/javascript">
function disable()
{
document.getElementById("accept").disabled=true
}
function enable()
{
document.getElementById("accept").disabled=false
}
</script>
</head>
<body>
<input type="checkBox" οnclick="if (this.checked) {enable()} else {disable()}">同意协议
<br />
<br />
<br />
<input type="button" id="accept" disabled="true" value="确定">
</body>
</html>