Semaphore Locking Operation IN INFORMIX OnLine 7.1 Stored Procedure

I am involved in the migrations of an Oracle 7.x application to an Informix Online 7.1 Database. One of the requirements is for implementing something that acts like an Oracle sequence. (for those of you who haven't dealt with these objects they behave something like this Once created: SELECT <sequence_name>.Nextval FROM DUAL; Will return the next value of the sequence an update the next value by an increment value defined when the sequence is created.) I have figured out a way on paper to do these using a table and stored procedures Something like this: CREATE TABLE ORA_SEQUENCES ( SEQUENCE_NAME varchar(20), NEXTVAL INT; INCREMENT_BY SMALLINT); CREATE PROCEDURE getnextseq( sequence varchar(20)) RETURNING INT; DEFINE CURRENTVALUE INT; DEFINE NEXTVALUE INT; DEFINE INCR INT; SELECT NEXTVAL, INCREMENT_BY INTO CURRENTVALUE, INCR FROM ORA_SEQUENCES WHERE SEQUENCE_NAME = SEQUENCE FOR UPDATE; -- Select current sequence and Lock row LET NEXTVALUE = CURRENTVALUE + INCR; -- increment sequence to generate nextvalue UPDATE ORA_SEQUENCES SET NEXTVAL = NEXTVALUE WHERE SEQUENCE_NAME = SEQUENCE; -- update sequence COMMIT WORK; -- conclude transaction RETURN CURRENTVALUE; -- send back sequence value END PROCEDURE problem I'm having is Whenever I include the FOR UPDATE clause I get a syntax error Documentation is vague on this point but seams to indicate the for update clause can only be used with a cursor. The problem is the documentation seams to suggest that a stored procedure cannot have an explicit cursor. So really I have three questions. 1) How can I implement this kind of Semaphore operation in an Informix Stored Procedure? 2) Is this the best way to approach this particular problem (implementing sequences)? 3) Is my admittedly limited understanding of Informix SPL correct (i.e. no cursors allowed)? AT this point I'm willing to take any constructive comments; - Sean U.M. McGrath urielmcg@worldnet.att.net