您从哪里包含jQuery库?谷歌JSAPI?CDN?
<script src="https://www.google.com/jsapi"></script><script>google.load('jquery', '1.3.1');</script>
编辑:
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.3/jquery.min.js"></script>
编辑2:
<script src="//ajax.googleapis.com/ajax/libs/jquery/1.4.3/jquery.min.js"></script>
http: