> How do I catch exceptions in IBO(look at ???? above)

The most useful exception classes are...

Client based exceptions
EIB_Error = class(Exception);

Exceptions as a result of server (ISC) generated errors.
EIB_ISCError = class(EIB_Error)

To see the others lookup EIB* in the index of the online help.

HTH

Geoff Worboys
Telesis Computing