实际是调用了两次，Ajax类内部又调用一次。
服务端（Java版）需要做下转码：
String message = request.getParameter("message");
message = URLDecoder.decode(message, "UTF-8");
2、Demo.html
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>Ajax类</title>
<script src="Ajax.js" src="Ajax.js"></script>
<style type="text/css"><!--
#Layer1 {
position:absolute;
left:670px;
top:11px;
width:15px;
height:15px;
z-index:10000;
background-color:#FF0000;
font-size:13;
border:none;
visibility:hidden;
}
--></style><style type="text/css" bogus="1">#Layer1 {
position:absolute;
left:670px;
top:11px;
width:15px;
height:15px;
z-index:10000;
background-color:#FF0000;
font-size:13;
border:none;
visibility:hidden;
}</style>
</head>
<body>
<div id="Layer1"><img src="indicator_flower.gif" src="indicator_flower.gif" width="15" /></div>
<script type="text/javascript" language="javascript"><!--
function processRequest(http_request, _val, _loading_img){
alert(http_request.responseXML.documentElement.xml);
//alert(http_request.responseText);
funHide(_loading_img);
}
// --></script>
<script type="text/javascript" language="javascript"><!--
var url = "http://www.w3schools.com/xml/simple.xml";
var data = "";
var ajax = new AjaxDO();
function btnAjax1(){
//var ajax = new AjaxDO();
//ajax.InitHttpRequest();
ajax.abort();
ajax.setLoadingImg(document.getElementById("Layer1"));
ajax.setOnReadyStateChange(processRequest);
ajax.Open("GET", url, true); //异步模式，程序继续执行
ajax.Send("");
}
function btnAjax2(){
//var ajax = new AjaxDO();
//ajax.InitHttpRequest();
ajax.abort();
ajax.Open("GET", url, false); //非异步模式，程序等待
