Help needed with running a Java Program

Bear with me, for I am a newbie at Java coding.

I was able to succesfully compile my Java source and create the class file 
using the JAVAC command in QSHELL Interpreter.

I can see the .class file exist in the area I compiled it, but I am unable to 
run the program from the AS/400 using the RUNJVA command.  I wrote a CL to set 
the Environment to be the same as the Classpath I compiled the program under.  
I still receive the following error:

Attaching Java program to /QIBM/UserData/myProgram.class.                 
java.lang.NoClassDefFoundError: myProgram                                 
      java/lang/Error.<init>(Ljava/lang/String;)V+1 (Error.java:53)          
Java program completed with exit code 1                                      
 
Any suggestions?  By the way, I am on a older version of the OS V4R4.