In addition to Jim's suggestion, you could row buffer the source table; this would allow you to error check before committing any changes.

>When I leave a textbox linked to a canidate index, how can I come up with the "Uniqueness Violated..." right away after I leave the field? Because if I'm not mistaken, I think it waits to validate uniquness when it leaves the record. I suppose I could use the Rule instead, but how would that look? I can't safely put a seek in a rule on that table, can I?