Print File Defintions on the AS400

I'm trying to convert our S/36 COBOL programs to the AS400.  When I do a report 
the program blows up because the print file is not 'defined'.  When I 'create' 
the print file the program works.  What have I done wrong in my system 
definition?  As a COBOL programmer I NEVER had to worry about the DD name that 
I used.  I've never had to 'create' a print file.

My assign's look like this:

ASSIGN PRINT-FILE  ASSIGN PRINTER-PRFILE. 

If you could help me it would be greatly appreciated.

Phil Campbell
Wisco Envelope

pcampbell@xxxxxxxxxxxx