Use of Opennlp

[Congmin min]

Hello, I am new to this tools. I downloaded 1.5 version, and added the 3 jar
files into my windows 7 environment variable:
C:\Program Files\Apache Software Foundation\Tomcat
7.0\webapps\nlpTools\WEB-INF\classes\nlpTools\openNLP\lib\jwnl-1.3.3.jar;
C:\Program Files\Apache Software Foundation\Tomcat
7.0\webapps\nlpTools\WEB-INF\classes\nlpTools\openNLP\lib\maxent-3.0.0.jar;
C:\Program Files\Apache Software Foundation\Tomcat
7.0\webapps\nlpTools\WEB-INF\classes\nlpTools\openNLP\lib\opennlp-tools-1.5.0.jar

Then I wrote a helloWorld.java to test it, but it says the package can't be
found:

import opennlp.tools.chunker.ChunkSample;

public class Test{
    public static void main(String[] args) {
        System.out.println(" NLP tools ... ");
}


c:\>javac Test.java
Test.java:1: package opennlp.tools.chunker does not exist
import opennlp.tools.chunker.ChunkSample;
                            ^
1 error

Where was I wrong? Thanks.