js中的AJAX

js中ajax get请求的写法 
var xhr=new xmlhttprequest();
            xhr.open('get','http://rap2api.taobao.org/app/mock/229494/news?content='+ inp.value)
            xhr.send();
            xhr.onreadystatechange=function () {
                if (xhr.readystate==4) {
                    // console.log(xhr.responetext
                }
            }

js中post请求的写法
var xhr = new xmlhttprequest();
xhr.open('post',"http://192.168.1.5/archives/register.php",true);
// 如果是post请求 必须加上请求头
xhr.setrequestheader("content-type","application/x-www-form-urlencoded");
xhr.send("username="+user.value+'&password='+pass.value);
xhr.onreadystatechange =function(){
 if (xhr.readystate==4) {
 var obj = json.parse(xhr.responsetext);
 console.log(obj.responsecode);
 if (obj.responsecode=="0") {
 window.location.href = "denglu.html"
 }
 }
}