i want to logout from dashboard and I got the error message as shown below

I need to logout from dahboard.jsp and go to index.jsp but while I'm clicking the logout button it is showing the error message like this,

HTTP Status 404 - /Project/logout

type Status report

message /Project/logout

description The requested resource (/Project/logout) is not available.

Apache Tomcat/6.0.20

the dashboard.jsp and the servlets login and logout are posted below, what might be the error in that.

dashboard.jsp

<div class="ends">
    <form action="logout" method="post" >
    <input type="submit" value="logout">
    </form>

    </div>

servlet page login login.java

 package com.signin;

 import java.io.IOException;

 import javax.servlet.RequestDispatcher;
 import javax.servlet.ServletException;
 import javax.servlet.http.HttpServlet;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 import javax.servlet.http.HttpSession;

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

import com.db.DBCon;

/** * Servlet implementation class login */ public class login extends HttpServlet {

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

    response.setContentType("text/html");
    PrintWriter out = response.getWriter();

    String uid=request.getParameter("uid");
    String pwd=request.getParameter("pwd");


    try {
        DBCon dbc = new DBCon();
        if(dbc.validateLogin(uid, pwd))
        {
            HttpSession session=request.getSession();
            session.setAttribute("userid",uid);

            response.sendRedirect("dashboard.jsp");
        }
        else
            out.println("<center><h3>Sign in Failed!</h3><br><a href='index.jsp'>Go to Sign up page</a></center>");
        dbc.closeCon();
    }
    catch(Exception e){ e.printStackTrace(); }
}

}

logout.java

 package com.signin;
import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;   
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

/** * Servlet implementation class logout */ public class logout extends HttpServlet {

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    // TODO Auto-generated method stub

    HttpSession session=request.getSession();
    session.removeAttribute("userid");
    session.invalidate();
    response.sendRedirect("index.jsp");

  }

}