I have a reservation program that I am writing and must have a check somehow to disallow identical entries.<BR><BR>I would like an error message to appear if someone enters in the exact fields that someone else has reserved:<BR>i.e. (building#, room #, start time, end time and date)<BR><BR>Is there a way for my MS Access table to disallow this, and spit up a page that informs the user of there error?