[AccessD] subform only allows one record

I need to set up a subform that only allows a single record to be entered.
I have a function in the subform that checks if the
recordsetclone.recordcount >0 and if so sets AllowAdditions = false.  This
works fine if any records already exist but if a new record is created, then
if the person does a page down to save the first record, they end up in a
second record.  I am firing this function I built from the OnCurrent of the
parent, as well as the OnCurrent of the subform itself.  Haven't tried yet
from before update.

Does anyone do this kind of thing?  If so how do you accomplish it?

John W. Colby
www.ColbyConsulting.com