ajax校验的js,证验不通过时禁用提交按钮

ajax校验的js,验证不通过时禁用提交按钮
被这个问题困扰了不少时间,把解决的函数记录下来留此存照.

	<script src="prototype-1.6.0.3.js" type="text/javascript"></script>
	<script src="json2.js" type="text/javascript"></script>
	<script type="text/javascript">
	function validateID() {
		var url = "validateID";
		var params = Form.Element.serialize("id");
		var myAjax = new Ajax.Request(url, {
			method : "post",
			parameters : params,
			onComplete : processResponse,
			asynchronous : true
		});
	}
	function processResponse(request) {
		var action = JSON.parse(request.responseText);
		$("tip").innerHTML = action.tip;
		if (action.flag) {
			document.all("submit").disabled = true;
		} else {
			document.all("submit").disabled = false;
		}
	}
	function refresh() {
		document.getElementById("authImg").src = "auth.jpg?now=" + new Date();
	}
</script>