换手率与股票升跌

------------------------------------------------jsp页面-------------------------------------------------------------
<%@ page language="java" pageEncoding="gb2312"%>
<html>
  <head>
<title>TEST页面</title>
  <script language="JavaScript" src="mesgload.js"></script>
  </head>
  <body>
  <br>
  <div align="center">
       <table width="70%" border="1">
       <tr>
       <td>
       <div id='hade' style="display: none"></div>
       <div id='code' style="display: none"></div>
       </td>
       </tr>
       <tr>
       <td align="center">
       <input type="button" value="提交" onClick="Display()">   <!-- 提交按钮 -->
       </td>
       </tr>
       </table>
   </div>
  </body>
</html>

------------------------------------------------mesgload.js----------------------------------------------------------------
var req;
var url="frame";
function Display(){
    if(window.XMLHttpRequest){
        req = new XMLHttpRequest();   //创建XMLHttpRequest对象   
    }
    else if(window.ActiveXObject){
        req = new ActiveXObject("Microsoft.XMLHTTP");
    }
    if(req){
        req.open("POST",url,true); //建立请求
        req.onreadystatechange = callback; //指定回调函数
        req.send(null);
    }
}
function callback(){
    if(req.readyState == 3){
            sendMessage();
    }
    if(req.readyState == 4){
        if(req.status == 200){
    alert("数据正在传送中，请点击<确定>按钮");
    alert("数据发送完毕!");
            sendcompMessage();   
   
    }
    }
    }
    function sendMessage(){
            var content = document.getElementById('code');
            var content1= document.getElementById('hade');
            content.style.display = "";
            content1.style.display ="none";
            content.innerHTML = "页面LOADING....";
        }
    function sendcompMessage(){
        var content = document.getElementById('hade');
        var content1 = document.getElementById('code');
        content1.style.display="none";
        content.style.display="";
        content.innerHTML = "页面SUCCESS!";
    }

---------------------------------------------------------LoadServlet -----------------------------------------------------------
public class LoadServlet extends HttpServlet {
    public LoadServlet() {
        super();
    }
    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        response.setContentType("text/html");      //设置字符编码和头部信息
        response.setHeader("Cache-Control", "no-cache");
        System.out.println("服务器已经收到消息!");
        response.getWriter().write(""); //返回空字符串
       
    }

    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        doGet(request,response);
    }
}
-------------------------------------------------------web.xml-----------------------------------------------------------------
<servlet>
    <servlet-name>frame</servlet-name>
    <servlet-class>messageload.LoadServlet</servlet-class>
  </servlet>

  <servlet-mapping>
    <servlet-name>frame</servlet-name>
    <url-pattern>/frame</url-pattern>
  </servlet-mapping>