//定义XMLHttp实例
var xmlHttp;
function createXMLHttpRequest(){
//开始初始化XMLHttpRequest对象
if(window.ActiveXObject){
//IE浏览器
xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
}else if(window.XMLHttpRequest){
//Mozilla浏览器
xmlHttp = new XMLHttpRequest();
}
if(xmlHttp){
xmlHttp.open("GET",url,false);
xmlHttp.onreadystatechange=function(){setState(greens,reds,contains)};
xmlHttp.send(null);
}
}
//回调函数举例
//返回的4种状态
function setState(greens,reds,contains){
var contains = document.getElementById("contain");
if(xmlHttp.readyState == 0){
contains.innerHTML = "正在初始化";
}
if(xmlHttp.readyState == 1){
contains.innerHTML = "正在准备发送请求";
}
if(xmlHttp.readyState == 2){
contains.innerHTML = "正在发送请求";
}
if(xmlHttp.readyState == 3){
contains.innerHTML = "正在接收数据";
}
if(xmlHttp.readyState == 4){
//信息已经成功返回,开始处理信息
if(xmlHttp.status == 200){
contains.innerHTML = xmlHttp.responstText; //返回值
}
}
}
var xmlHttp;
function createXMLHttpRequest(){
//开始初始化XMLHttpRequest对象
if(window.ActiveXObject){
//IE浏览器
xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
}else if(window.XMLHttpRequest){
//Mozilla浏览器
xmlHttp = new XMLHttpRequest();
}
if(xmlHttp){
xmlHttp.open("GET",url,false);
xmlHttp.onreadystatechange=function(){setState(greens,reds,contains)};
xmlHttp.send(null);
}
}
//回调函数举例
//返回的4种状态
function setState(greens,reds,contains){
var contains = document.getElementById("contain");
if(xmlHttp.readyState == 0){
contains.innerHTML = "正在初始化";
}
if(xmlHttp.readyState == 1){
contains.innerHTML = "正在准备发送请求";
}
if(xmlHttp.readyState == 2){
contains.innerHTML = "正在发送请求";
}
if(xmlHttp.readyState == 3){
contains.innerHTML = "正在接收数据";
}
if(xmlHttp.readyState == 4){
//信息已经成功返回,开始处理信息
if(xmlHttp.status == 200){
contains.innerHTML = xmlHttp.responstText; //返回值
}
}
}