ajax基础

var http;
function xuanti(obj){

var url=null;//写action路径
sendRequest(url);
}
//创建XML请求
function createXMLHttpRequest(){
if(window.XMLHttpRequest){
http=new XMLHttpRequest();
}else if(window.ActiveXObect){
try {
http= new ActiveXObject("Msxml2.XMLHTTP");
} catch (e) {
try {
http = new ActiveXObject("Microsoft.XMLHTTP");
} catch (e) {}
}
}
}
//发送请求
function sendRequest(url){
createXMLHttpRequest();
http.open("post",url,true);
http.onreadystatechange=process;
http.send();
}
//回调函数，处理action返回的结果
function process(){
if(http.readyState==4){
if(http.status==200){
var result=http.responseText; }else{ window.alert("请求异常"); } } }