Help with cprdata

I'm having a senior citizen moment I think.  I just can't see why this puppy
is blowing up on me with a nasty template error.

What am I missing?  The C manual defines it like so:
int cprdata (_SPCPTR result,
int result_length,
_SPCPTRCN source,
int src_length);

And my RPG code is:

     d Compress        pr            10i 0 Extproc('cprdata')
     d   Output                   32000a   Options(*Varsize)
     d   OutputLen                   10i 0 Value
     d   Source                   32000a   Options(*Varsize)
     d   SourceLen                   10i 0 Value

     D Compressed      S             44a
     D CompressedLen   S              2s 0
     D Source          S             52a

      /Free
        Source = *All'Jon and Susan - ';
        Dsply Source;
        CompressedLen = Compress(Compressed: %Size(Compressed):
                                 Source:     %Size(Source));

Jon Paris
Partner400
www.Partner400.com