用Ajax读取Text格式的数据

　　用Ajax读取Text格式的数据，只需要读取XMLHttpRequest对象返回的responseText属性即可。代码如下：

　　1、Client - helloworld.htm

<!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.txt", 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){
            // 显示返回结果
            alert("responseText's value: " + xmlHttp.responseText);
        }
    }
}
</script>
</head>
<body>
    <div>
        <input type="button" value="return ajax responseText's value"
                onclick="startRequest();" />
    </div>
</body>
</html>

2、Server - data.txt

hello world!

附源码：responseText.rar