<script language="javascript" type="text/javascript">
//AJAX对象请求的一个很好的XMLHttpRequest对象建立的例子
//===========================================================================

function createXMLHttp(){
    var objXMLHttp;
    if (window.XMLHttpRequest) {        
        objXMLHttp = new XMLHttpRequest(); //针对FireFox，Mozillar,Opera,Safari，IE7，IE8
        if (objXMLHttp.overrideMimeType){ //针对某些特定版本的mozillar浏览器的BUG进行修正
            objXMLHttp.overrideMimeType("text/xml");
        }
        }else if(!objXMLHttp && window.ActiveXObject){        
        var activexName = ["MSXML2.XMLHTTP.6.0","MSXML2.XMLHTTP.5.0","MSXML2.XMLHTTP.4.0","MSXML2.XMLHTTP.3.0","MSXML2.XMLHTTP","Microsoft.XMLHTTP"];
        for (var i = 0; i < activexName.length; i++) {
                try{
                objXMLHttp = new ActiveXObject(activexName[i]);                
                }catch(e){
        continue;
                }
            if(objXMLHttp) break;
            }
    }    
    if(objXMLHttp){
        return objXMLHttp;
    }else{
        alert("Can not create XMLHttpRequest object, maybe update your browser to new version.\n\nXMLHttpRequest对象创建失败! 请升级你的浏览器");
        return;
    }
}



//以上是建立AJAX请求的对象，以下是AJAX建立的模型

function doAjax(){
    var xmlHR;
    var goURL="";
    if(!xmlHR) xmlHR=createXMLHttp();
    xmlHR.open('GET', goURL, true);  //goURL为请求URL
    //xmlHR.open('POST', goURL, true);  //OR
    xmlHR.onreadystatechange = callBackFun;  
    xmlHR.withCredentials = "true";  
    xmlHR.send(null);  
      
    function callBackFun(){
        if(xmlHR.readyState == 4) {  
               if(xmlHR.status == 200) { 
                var r = xmlHR.responseText; 
                //alert(r);
                
                
            }
        } 
    }
}

</script>

------解决方案--------------------

把网站部署到本机的IIS/apache等上