AJax

================================首先把它写到<script>标签里========================================

if (window.ActiveXObject && !window.XMLHttpRequest) {  window.XMLHttpRequest = function() {   var msxmls = ['Msxml2.XMLHTTP.5.0','Msxml2.XMLHTTP.4.0','Msxml2.XMLHTTP.3.0','Msxml2.XMLHTTP','Microsoft.XMLHTTP'];   for (var i = 0; i < msxmls.length; i++) {    try {     return new ActiveXObject(msxmls[i]);    } catch (e) {}   }   return null;  }; }

var http = new XMLHttpRequest();

===点击事件，发送请求===

function sendRequest() {

    //编码 是传进来的参数    //data = encodeURIComponent(d);

   //后台转码：String d = request.getParameter("d");   //d = new String(d.getBytes("iso-8859-1"),"UTF-8");  var d = new Date();  //确定请求的地址和请求的方式

  http.open("GET","<%=path%>/servlet/Servlet2?" + d.getTime(), true);  //设置回调函数  http.onreadystatechange=getRespnse;  //如果是GET请求，请求数据为null  http.send(null); }

、、、、、、、、如果是POST请求

function sendRequest(d){  d = encodeURIComponent(d);  http.open("post", '<%=path%>/servlet/ajax3', true);  //设置请求头  http.setRequestHeader("Content-Type","application/x-www-form-urlencoded");  http.onreadystatechange=getResponse;   http.send("d=" + d);//这里往过传数据 }

 

====回应===============

function getRespnse(){  if(http.readyState==4){   var div = document.getElementByIdx_x("date");   var s = http.responseText;   div.innerHTML = s;  }}

Servlet通过out.print("XXX");把值传过来，JSP页面用http.responseText来接受！