java.lang.NoClassDefFoundError: gnu/io/CommPortIdentifier

[YAY]

Hello!
I installed rxtx this way:

1. Copy rxtxParallel.dll to c:\Program Files\Java\jdk1.6.0_01\jre\bin\
2. Copy rxtxSerial.dll to c:\Program Files\Java\jdk1.6.0_01\jre\bin\
3. Copy RXTXcomm.jar to c:\Program Files\Java\jdk1.6.0_01\jre\lib\ext\

When I run this program

import gnu.io.*;

public class SimpleRead
{
	static void listPorts()
    {
        java.util.Enumeration<CommPortIdentifier> portEnum = CommPortIdentifier.getPortIdentifiers();
        while ( portEnum.hasMoreElements() ) 
        {
            CommPortIdentifier portIdentifier = portEnum.nextElement();
            System.out.println(portIdentifier.getName()  +  " - " +  getPortTypeName(portIdentifier.getPortType()) );
        }        
    }
    
    static String getPortTypeName ( int portType )
    {
        switch ( portType )
        {
            case CommPortIdentifier.PORT_I2C:
                return "I2C";
            case CommPortIdentifier.PORT_PARALLEL:
                return "Parallel";
            case CommPortIdentifier.PORT_RAW:
                return "Raw";
            case CommPortIdentifier.PORT_RS485:
                return "RS485";
            case CommPortIdentifier.PORT_SERIAL:
                return "Serial";
            default:
                return "unknown type";
        }
    }
	
    public static void main(String[] args) 
    {
		listPorts();
	}
}

I get following error

Exception in thread "main" java.lang.NoClassDefFoundError: gnu/io/CommPortIdenti
fier
        at SimpleRead.listPorts(SimpleRead.java:7)
        at SimpleRead.main(SimpleRead.java:36)
Caused by: java.lang.ClassNotFoundException: gnu.io.CommPortIdentifier
        at java.net.URLClassLoader$1.run(Unknown Source)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        ... 2 more

Please help!