Newbie: CPF5068 "Prog. device RESERVDF not found in file RESERVDF"

Hi all, 

I'm a student new to OS/400. I'm having trouble running a simple CL
script, RESERVCL. Googling for the error message has not helped.


Error Message
=============

The script compiles fine. When I run it, I get a CPF5068:

 Cause . . . . . :   ILE Control language (CL) procedure RESERVCL in module
   RESERVCL in program RESERVCL in library DB233A26A1 detected an error at
   statement number 0000000107.  Message text for CPF5068 is: Program device
   RESERVDF not found in file RESERVDF in library DB233A26A1.

The Job Log says:

 Message . . . . :   Program device RESERVDF not found in file RESERVDF in
   library DB233A26A1.
 Cause . . . . . :   The operation supplied the wrong program device name.
 Recovery  . . . :   Do one of the following and try the request again:
     -- Change the program to specify the correct program device name.
     -- Change the program to acquire the correct program device for the file
   before using the program device for read or write operations.


Contents of Script
==================

PGM
DCLF db233a26a1/reservdf
SNDRCVF
ENDPGM


Additional Info
===============

Here's a DSPLIB of DB233A26A1:

Object      Type      Attribute               Size  Text
RESERVCL    *PGM      CLLE                   69632
QCLLESRC    *FILE     PF                     24576
QDDSSRC     *FILE     PF                     24576
RESERVCL    *FILE     PF                      8192
RESERVDF    *FILE     DSPF                    4096
TRESERVDF   *FILE     DSPF                    4096

TRESERVDF is an old backup.

DB233A26A1 is not in my library list, but AFAIK it does not need to be.

I don't even know what a "program device" is, and my textbook provides
no additional info. I wish I had a better textbook.


My Question
===========

How do I get the SNDRCVF to work and show the DDS screen I designed? Any
help would be greatly appreciated.

P.S. Was this post too long? :)

Regards,
Jason Spiro
Toronto, Canada