学习Servlet遇到的问题,找不到javax.servlet包

我安装的是jdk1.5.0
tomcat5.0
环境变量设置如下:JAVA_HOME
C:\Program Files\Java\jdk1.5.0TOMCAT_HOME
C:\Program Files\Apache Software Foundation\Tomcat 5.0CLASSPATH
.;%JAVA_HOME%\lib;%TOMCAT_HOME%\common\lib;PATH
%JAVA_HOME%\bin;我编写HelloWorldExample.java如下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("<html>");
        out.println("<head>");     String title = rb.getString("helloworld.title");     out.println("<title>" + title + "</title>");
        out.println("</head>");
        out.println("<body bgcolor=\"white\">");        out.println("<a href=\"../helloworld.html\">");
        out.println("<img src=\"../images/code.gif\" height=24 " + "width=24 align=right border=0 alt=\"view code\"></a>");
        out.println("<a href=\"../index.html\">");
        out.println("<img src=\"../images/return.gif\" height=24 " +
                    "width=24 align=right border=0 alt=\"return\"></a>");
        out.println("<h1>" + title + "</h1>");
        out.println("</body>");
        out.println("</html>");
    }
}javac HelloWorldExample.javaHelloWorld2.java:3: package javax.servlet.http does not exist
import javax.servlet.http.*;
^
1 error
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