Vivek Gajabe

What's the difference between JDK Version 1.1,1.2,1.3,1.4,1.5 and 1.6?
which things were added in each version?

Page No 84 from Head First Servlet & Jsp.
When i try to compile this program(BeerSelect.java), it shows
1.package com.example.model does not exist.
import com.example.model.*;
^
2.Cannot find symbol class BeerExpert
BeerExpert be = new BeerExpert();
^ ^
The path com.example.model exist & even BeerExpert.java exist,it compiles fine.
But BeerSelect.java can't import BeerExpert.java.
what's the problem?

Thanks a lot!!!
It's working. I have not included the jar file name in classpath, thats why it showed me an error.
Thanks!!!

import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
public class Ch1Servlet extends HttpServlet{
public void doGet(HttpServletRequest request,HttpServletResponse response) throws IOException {
PrintWriter out = response.getWriter();
/* some code */
}
}
*******************************
Error
1.package javax.servlet does not exist
import javax.servlet.*;
^
2.package javax.servlet.http does not exist
import javax.servlet.http.*;
^
3.cannot find symbol for class HttpServlet,class HttpServletRequest & class HttpServletResponse.

Please note that i have installed jdk 1.6,jre 1.6 & apache tomcat 6.0.Classpath is also set properly.