Servlet call from JSP using AJAX problem.

[Ignatius88]

<script>
var xhr = null;

function createRequest() {
	if(window.ActiveXObject) {
	        xhr = new ActiveXObject("Microsoft.XMLHTTP");
	} else {
		xhr = new XMLHttpRequest();
	}
}
		 
function sendRequest(url, param, callback, method) {
	createRequest();
	var httpMethod = (method!='POST' && method!='post') ? 'GET' : 'POST';
	var httpParam = (param==null || param=='') ? null : param;
	var httpURL = url;
	
	if(httpMethod=='GET' && httpParam!=null) {
		httpURL = httpURL+"?"+httpParam;    // test.jsp?idx=12
	}
	
	xhr.onreadystatechange = callback;
	xhr.open(httpMethod, httpURL, true);
	xhr.setRequestHeader("Content-Type", "application/x-www-form-	urlencoded");
	xhr.send(httpMethod=='POST' ? httpParam : null);
}

function valuecheck() {
	var value;
	for (var i = 0; i < document.data.radio_rate.length; i++) {
		if (document.data.radio_rate[i].checked) {
			value =  document.data.radio_rate[i].value;
		}
	}
	
	var param = "value=" + encodeURIComponent(value) + "&mid=" + 	encodeURIComponent(<%=bean.getMovie_Id()%>);
	endRequest("/Rate", param, idResult, "post");
}
		
function idResult() {
	if (xhr.readyState == 4) {
		if (xhr.status == 200) {
			alert("inserted");
		}
	}
}
</script>

<form name = "data" method = "post">
	<p>
	<font size = "4">
		Rate: 1<input name="radio_rate" type="radio" value="1" onclick="valuecheck()"/>
		2<input name="radio_rate" type="radio" value="2" onclick="valuecheck()"/> 
		3<input name="radio_rate" type="radio" value="3" onclick="valuecheck()"/> 
		4<input name="radio_rate" type="radio" value="4" onclick="valuecheck()"/>
		5<input name="radio_rate" type="radio" value="5" onclick="valuecheck()"/>
	</font>
	</p>
</form>

web.xml  
<servlet>
	<servlet-name>RateServlet</servlet-name>
	<servlet-class>lasec.servlet.RateServlet</servlet-class>
</servlet>
<servlet-mapping>
	<servlet-name>RateServlet</servlet-name>
  	<url-pattern>/Rate</url-pattern>
</servlet-mapping>

package lasec.servlet;

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

import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import lasec.util.DBManager;

/**
 * Servlet implementation class RateServlet
 */
@WebServlet("/RateServlet")
public class RateServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;
    private int serviceCounter = 0;
    private boolean shuttingDown;
	private DBManager manage;  
	
	/**
	 * @see Servlet#init(ServletConfig)
	 */
	public void init() throws ServletException {
		// TODO Auto-generated method stub
		super.init();
		manage = new DBManager();
		System.out.println("Init()");
	}

	protected synchronized void enteringServiceMethod() {
		serviceCounter++;
	}
	
	protected synchronized void leavingServiceMethod() {
		serviceCounter--;
	}
	
	protected synchronized int numServices() {
		return serviceCounter;
	}
	
	protected synchronized void setShuttingDown(boolean flag) {
		shuttingDown = flag;
	}
	
	protected synchronized boolean isShuttingDown() {
		return shuttingDown;
	}
	
	/**
	 * @see Servlet#destroy()
	 */
	public void destroy() {
		// TODO Auto-generated method stub
		if (numServices() > 0) {
			setShuttingDown(true);
		}
		
		while (numServices() > 0) {
			try {
				Thread.sleep(1000);
			} catch (InterruptedException e) {
			}
		}
		
		manage = null;
	}

	/**
	 * @see HttpServlet#service(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		enteringServiceMethod();
		try {
			super.service(request, response);
		} finally {
			leavingServiceMethod();
		}
	}
	
	protected void processRequest(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		response.setContentType("text/html; charset=utf-8");
		request.setCharacterEncoding("utf-8");
		
		PrintWriter out = response.getWriter();
		String mid = request.getParameter("mid");
		String value = request.getParameter("value");
		
		HttpSession session = request.getSession(true);
		String uid = (String) session.getAttribute("uid");
		
		try {
			manage.insertMovieRate(uid, mid, value);
			out.print("success");
		} catch (Exception e) {
			out.print("fail");
		}
	}

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		processRequest(request, response);
	}

	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		processRequest(request, response);
	}

}

If I press the radio button, I want to send the values to the servlet so it can perform database jobs. However, it does not work. localhost:8080/<Project name>/Rate?uid=&mid= works.

Is something wrong? I am using JBoss 6.0 AS.