Clause not correct for procedure or function.

Well...this seems odd. I'm trying to create a procedure like this in
interactive SQL (STRSQL):

CREATE PROCEDURE NEWSYS/MSP_VALIDATESTORE(INOUT IOStore CHAR ( 3))
LANGUAGE RPGLE SPECIFIC NEWSYS/MSPSRVPGM(MSP_VALIDATESTORE) NOT
DETERMINISTIC READS SQL DATA EXTERNAL NAME
'NEWSYS/MSPSRVPGM(MSP_VALIDATESTORE)' PARAMETER STYLE GENERAL

And I get a SQL0491 with reason code 10: 10 -- For external functions and
procedures, LANGUAGE SQL is not allowed
and there must not be a routine body.

So I went into Navigator and played around, and got it to where I think I
want it. Is there a difference between what you can do in interactive SQL
and what you can do in Navigator? Thanks!