Invalidating a Session help

Question

When a user logs out the following servlet is called. The problem is that when the back button is hit they can get back in without signing in again. User authentication is done with a bean with Session scope. Does the invalidate() not destroy the bean as well?
import java.io.*;
import javax.servlet.ServletException;
import javax.servlet.http.*;
public class LogOutServlet extends HttpServlet
     protected void doGet(HttpServletRequest request,
     HttpServletResponse response) throws ServletException, IOException {
     HttpSession hs;
     hs=request.getSession();
     hs.invalidate();
     response.sendRedirect("../index.jsp");
help me OB1, you're my only hope.
Thanks
C.

Answer 1

Well, you don't clear the cache, you prevent pages from being cached.
Look at this thread: http://forum.java.sun.com/thread.jsp?forum=45&thread=562372 which states clearly how to do it. Note, you would have to add the response.setHeaders on top of every page that you don't want cached.