PL/Java problem.

Greetings,

Before I start I must admit that I am a newbie to Java.  This means that
this might actually be my problem and NOT a software issue, but I need help.

I am attempting to execute the "Hello World" demo from
http://wiki.tada.se/wiki/display/pljava/User+Guide which is part of the
user guide for the software.  In the process I created the following
class, and compiled (JAR) with NO errors:

   package com.mycompany.helloworld;
   public HelloWorld {    public String helloWorld() {        return
"Hello World";    }
   }

Next I ran psql  with the following result:

#psql -U mfgadmin mlp204
Password for user mfgadmin:
Welcome to psql 8.1.3, the PostgreSQL interactive terminal.

Type:  \copyright for distribution terms
       \h for help with SQL commands
       \? for help with psql commands
       \g or terminate with semicolon to execute query
       \q to quit

Warning: Console code page (437) differs from Windows code page (1252)
         8-bit characters may not work correctly. See psql reference
         page "Notes for Windows users" for details.

mlp204=# select sqlj.install_jar('file:///Java source/helloworld.jar',
'hellowor
ld_jar', false);
 install_jar
-------------

(1 row)

mlp204=# select sqlj.set_classpath('public', 'helloworld_jar');
 set_classpath
---------------

(1 row)

mlp204=# CREATE OR REPLACE FUNCTION helloworld()
mlp204-#   RETURNS "varchar" AS
mlp204-#     'com.mycompany.helloworld.HelloWorld.helloWorld'
mlp204-#   LANGUAGE 'java' VOLATILE;
CREATE FUNCTION
mlp204=# select * from helloworld();
ERROR:  java.lang.ClassNotFoundException:
com.mycompany.helloworld.HelloWorld
mlp204=#

Everything seems to be working fine except I receive a
"ClassNotFoundException".  Any help in understanding what I did wrong
would be appreciated.

Thanks Scott.