i have a building layer that needs periodic updating. i want to create a unique, unchanging building id for each building. i thought i would create a field "BLDG-ID" and field calculate the object id + 1. once i have done that on my initial building layer snapshot, is there a method/idea/script to automatically assign a bldg id based on the highest number within "BLDG-ID" +1, when i digitize a new building? reason i ask is because object id's can change depending on how the layer gets moved around from database to database. thoughts?