让页面的元素都失效
<!DOCTYPE html>
<html>
<head>
<title>*选择器</title>
<script src="http://libs.baidu.com/jquery/1.9.0/jquery.js" type="text/javascript"></script>
</head>
<body>
<form action="#">
<input />
<input />
<input />
<input />
</form>
<script type="text/javascript">
$("form *").attr("disabled", "true");
</script>
</body>
</html>