I have a form with subform working but with one issue - when I enter data
into a row I start on the next row, but get error about duplicate key. I
press the escape key, it clears the data I just tried inputing, and it
updates the key field. The key field causing the error uses this in the
default value property field-

=Nz(DMax("SongID","MusicOnPC_Songs"),0)+1

Is there something missing to make it update after I tab out of the last
field for that row, and move into the next row?