用Ajax读取XML格式的数据

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html>
<head>
<title>Ajax Hello World</title>
<script type="text/javascript">
var xmlHttp;

function createXMLHttpRequest(){
if(window.ActiveXObject){
xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
}
else if(window.XMLHttpRequest){
xmlHttp = new XMLHttpRequest();
}
}

function startRequest(){
createXMLHttpRequest();
try{
xmlHttp.onreadystatechange = handleStateChange;
xmlHttp.open("GET", "data.xml", true);
xmlHttp.send(null);
}catch(exception){
alert("您要访问的资源不存在!");
}
}

function handleStateChange(){
if(xmlHttp.readyState == 4){
if (xmlHttp.status == 200 || xmlHttp.status == 0){
// 取得XML的DOM对象
var xmlDOM = xmlHttp.responseXML;
// 取得XML文档的根
var root = xmlDOM.documentElement;
try
{
// 取得<info>结果
var info = root.getElementsByTagName('info');
// 显示返回结果
alert("responseXML's value: " + info[0].firstChild.data);
}catch(exception)
{

}
}
}
}
</script>
</head>
<body>
<div>
<input type="button" value="return ajax responseXML's value"
onclick="startRequest();" />
</div>
</body>
</html>

2、Server - data.xml

<?xml version="1.0" encoding="GB2312" ?>
<root>
<info>hello world!</info>
</root>