<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>repeat</title></head>
<body>
<p>it seemed that the first Ajax should be vary easy!</p>
<p id="recieved"></p>
<input type="button" value="提交" onclick="getNewContent();">
<script>
var request = false;
try{
request = new XMLHttpRequest();
}catch(trymicrosoft){
try{
request = new ActiveXObject("Msxml2.XMLHTTP.6.0");
}catch(earlier){
try{
request = new ActiveXObject("Msxml2.XMLHTTP.3.0");
}catch(moreearlier){
try{
request = new ActiveXObject("Msxml2.XMLHTTP");
}catch(failed){
request = false;
}
}
}
}
if (!request) alert("no Ajax here");
function getNewContent(){
if (request) {
request.open("GET","target.xml",true);
request.onreadystatechange = hhh;
request.send(null);
}
}
function hhh() {
if (request.readyState == 4) {
//alert(request.status);
console.log(request.status);
var recievedText = document.getElementById('recieved');
var responceT =document.createTextNode(request.responseText);
recievedText.appendChild(responceT);
}
}
</script></body>
</html>
console.log(request.status) are as follows:
firefox: 
chrome:
Why are there two different statuses? Will this difference not occur if we use a server on the web?
![[Web front-end] Node.js quick start](https://img.php.cn/upload/course/000/000/067/662b5d34ba7c0227.png)
This blog has a detailed introduction
http://blog.csdn.net/iaiti/ar...
ajax was originally designed to be used on the server. It shouldn't be available locally. Something concrete. You can use chrome to open network and FF to open network to view