Error running on iSeries

Can someone give any insight to why this program will error when running on
the iSeries after a successful compile through the QShell.

import com.ibm.as400.access.*;

public class CheckJt400 {
        public static void main(String[] args)
        {

                System.out.println(AS400.CENTRAL);
                System.out.println(AS400.COMMAND);

*Error Line     System.out.println(AS400.getDefaultUser("10.10.1.10"));

                System.exit(0);
        }
}

Output from Qshell:

6
2
java.lang.NoClassDefFoundError: com/ibm/as400/access/AS400
      java/lang/Throwable.<init>(Ljava/lang/String;)V+4 (Throwable.java:90)
      CheckJt400.main([Ljava/lang/String;)V+0 (CheckJt400.java:7)


Thanks,
Mark Abbott