<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
 "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html>
    <head>
        <title>Ajax</title>
        <script type="text/javascript" language="javascript"
         src="prototype.js" ></script>
        <script type="text/javascript" language="javascript">
        function test() {
            var myAjax = new Ajax.Request(
                'http://www.wanfangdata.com.cn', 
                {
                    method: 'get', 
                    onComplete: showResponse
                }
            );
        }
        
        function showResponse(response) {
            $('divResult').innerHTML = response.responseText;
        }        
        
        var handle = {
            onCreate: function() {
                Element.show('loading');
            },
            onComplete: function() {
                if (Ajax.activeRequestCount == 0) {
                    Element.hide('loading');
                }
            }
        };
        Ajax.Responders.register(handle);//把handle注册到全局的Ajax.Responders，Ajax.Responders用来维护一个正在运行的Ajax对象列表
        </script>
    </head>
    <body>
    <input type="button" value="click" onclick="test()" />
    <div id="divResult" ></div>
    <div id='loading' style="display:none">
        <img src="loading2.gif">Loading
    </div>
    </body>
</html>