把这个代码用微软的ajax怎么实现??实现同样功能

<script type="text/javascript">

var http_request = false;

function send_request(url) {//初始化、指定处理函数、发送请求的函数

http_request = false;
//开始初始化XMLHttpRequest对象
if(window.XMLHttpRequest) { //Mozilla 浏览器
http_request = new XMLHttpRequest();
if (http_request.overrideMimeType) {//设置MiME类别
http_request.overrideMimeType('text/xml');
}
}
else if (window.ActiveXObject) { // IE浏览器
try {
http_request = new ActiveXObject("Msxml2.XMLHTTP");
} catch (e) {
try {
http_request = new ActiveXObject("Microsoft.XMLHTTP");
} catch (e) {}
}
}

if (!http_request) { // 异常，创建对象实例失败
window.alert("不能创建XMLHttpRequest对象实例.");
return false;
}
//http_request.onreadystatechange = processRequest;
// 确定发送请求的方式和URL以及是否同步执行下段代码
http_request.open("GET", url, true);
http_request.send(null);
var divv2= document.getElementById("divv2").innerHTML;
divv2.innerHTML = http_request.responseText;
}

</script>