AJAX Óà POST ºÍ GET ´«ÖµÎÊÌâ

=========================web.xml=======================================================
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5"
xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
  <servlet>
    <servlet-name>GetAndPostExample </servlet-name>
    <servlet-class>com.hereinfo.GetAndPostExample </servlet-class>
  </servlet>

  <servlet-mapping>
    <servlet-name>GetAndPostExample </servlet-name>
    <url-pattern>/servlet/GetAndPostExample </url-pattern>
  </servlet-mapping> 
  <welcome-file-list>
    <welcome-file>TestPostAndGet.html </welcome-file>
  </welcome-file-list>
</web-app>
=================================Servlet=============================================
package com.hereinfo;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servl