我已经装好了jdk和tomcat，运行java程序和jsp都好好的，但是我要编译一个servlet,
就老出错，如下面这个例程
import java.io.*;
import java.text.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;

public class HelloWorldExample extends HttpServlet {


    public void doGet(HttpServletRequest request,
                      HttpServletResponse response)
        throws IOException, ServletException
    {
        ResourceBundle rb =
            ResourceBundle.getBundle("LocalStrings",request.getLocale());
        response.setContentType("text/html");
        PrintWriter out = response.getWriter();

        out.println("");
        out.println("");

    String title = rb.getString("helloworld.title");

    out.println("" + title + "");
        out.println("");
        out.println("");


    out.println("");
        out.println("");
        out.println("");
        out.println("");
        out.println("" + title + "");
        out.println("");
        out.println("");
    }
}

老是出错，
HelloWorldExample.java:8: package javax.servlet doe
import javax.servlet.*;
^
HelloWorldExample.java:9: package javax.servlet.htt
import javax.servlet.http.*;
^
HelloWorldExample.java:17: cannot resolve symbol
symbol  : class HttpServlet
location: class HelloWorldExample
public class HelloWorldExample extends HttpServlet
                                       ^
HelloWorldExample.java:20: cannot resolve symbol
symbol  : class HttpServletRequest
location: class HelloWorldExample
    public void doGet(HttpServletRequest request,
                      ^
HelloWorldExample.java:21: cannot resolve symbol
symbol  : class HttpServletResponse
location: class HelloWorldExample
                      HttpServletResponse response)
                      ^
HelloWorldExample.java:22: cannot resolve symbol
symbol  : class ServletException
location: class HelloWorldExample
        throws IOException, ServletException
                            ^
6 errors

是不是还要把tomcat下面一个什么.jar文件加到classpath中去呀，
是加那个呀，请大侠指教，多谢。

add Tomcat 4.1commonlibservlet.jar to your classpath