How to return SPL error message to ESQL/C app

The stored procedure language RAISE EXCEPTION statement allows you to specify an error message string. But the description of the RAISE EXCEPTION statement in the Stored Procedures section of the Informix Guide to SQL Reference (5.0) does not say anything about how this message is/can be used. I need to get these message into my ESQL/C applications. Through experimentation, I have been able to determine that the message is placed into sqlca.sqlerrm. So I now have access to the message. I need only determine when to look at the sqlerrm field and when to pass the sqlcode to the rgetmsg function to get the message. I've decided to do this by having the stored procedures always return an error code like -9999 and have my applications check for this code to determine where to get the error message from. This works but I have two concerns: (1) This capability doesn't seem to be documented anywhere so it might not exist in the next version we migrate to. (2) If I reuse an sqlcode already being used by Informix, I will interpret occurrences of the corresponding Informix error as a stored procedure-generated error. Anyone know if there is a better way to do this? Is this the correct way? Is, this the only way? Is it supported? By the way, the stored procedures are invoked via triggers so there's no opportunity for the procedures to simply return the error message using the RETURN statement. Thanks in advance for any help. Roger Tomas AG Communication Systems