Hi, sorry for my lack of experience with Firebird.
I have a Database with Firebird 2.0 which has, as seen through a tool utility program such as Marathon, in its structure, a list of User Defines Functions (the standard ones, I mean) such as ABS() (absolute value).

However, when I try to use it as in the following script:

Select <integer field> from <Table> where ABS(<integer field>) > 100

I always get the following error message:
ERROR: ISC ERROR MESSAGE:
ERROR: invalid request BLR at offset 165
ERROR: function ABS is not defined
ERROR: module name or entrypoint could not be found

Obviously, I get similar messages when trying to use it in my own application in Delphi 6.
I suppose that I have made something wrong, but can't realise what it is. Is there any help you can send to me?
Thank you very much.

Manuel