You mean to do this once, or multiple times? If multiple times, why?? <BR><BR>If once, there is no good way to do this, with a script or otherwise. I don't believe Access (I'm guessing you're using access) will let you convert a field to autonumber in a table that already has records in it. <BR><BR>If you really need to do this, you could make a new table thats designed the way you want it (with an autonumber) then use a query to put the records from the old table into the new one.