Depends where you are getting them. This is the table/relationships forum, we will usually not expose the tables and relationships to the users (or is it the other way around?), but say - in a form, you'd use the form error event
[tt]if dataerr = <the error> then
msgbox "your message"
responce = acdataerrcontinue ' this removes the default message
end if[/tt]
I never remember which errors this is, so just place a msgbox dataerr within the event procedure, then in the form enter a dupe, and you'll pick up the number to use in the above if statement. BTW - the forms forum is forum702
Roy-Vidar