when ($1 is null and $2 is not null) or ($1 is not null and $2 is null) then 0
That's the same as: when $1 is null != $2 is null then 0 Chris ---------------------------(end of broadcast)--------------------------- TIP 1: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly