XMLHttpRequest对象的使用

var xmlHttpRequest = null; //声明一个空对象以接收XMLHttpRequest对象
function ajaxSubmit()
{
if(window.ActiveXObject) // IE浏览器
{
xmlHttpRequest = new ActiveXObject("Microsoft.XMLHTTP");
}
else if(window.XMLHttpRequest) //除IE外的其他浏览器实现
{
xmlHttpRequest = new XMLHttpRequest();
}

if(null != xmlHttpRequest)
{
var v1 = document.getElementById("value1ID").value;
var v2 = document.getElementById("value2ID").value;
xmlHttpRequest.open("POST", "AjaxServlet", true);
//关联好ajax的回调函数
xmlHttpRequest.onreadystatechange = ajaxCallback;
//真正向服务器端发送数据
// 使用post方式提交，必须要加上如下一行
xmlHttpRequest.setRequestHeader("Content-Type","application/x-www-form-urlencoded");
xmlHttpRequest.send("v1=" + v1 + "&v2=" + v2);
}
}

function ajaxCallback()
{
if(xmlHttpRequest.readyState == 4)
{
if(xmlHttpRequest.status == 200)
{
var responseText = xmlHttpRequest.responseText;
document.getElementById("div1").innerHTML = responseText;
}
}
}