<script type="text/javascript" src="/js/jquery.js"></script>
<script type="text/javascript">
$(document).ready(function(){
$("div").ajaxStart(function(){
$(this).html("<img src='/img/demo_wait.gif' />");
$("button").click(function(){
$("div").load("/example/jq/demo_ajax_load.html");
<div id="txt"><h2>通过 AJAX 改变文本</h2></div>