you haven't given a clear explanation of your setup; however, if you mean
that the checkbox(es) in the form are bound to field(s) in the underlying
table, and the form displays *multiple records*, and you want to clear the
checkbox(es) in *all the records* at the same time...then use an Update
query to set the value of the Yes/No field to False, in the table. suggest
you run this query *before* opening the form, otherwise you'll have to
requery the form's RecordSource to see the changed field values.
hth