ms access updating field conditionally on form.activate - sql

Question

My question concerns situations where custom code is required to auto-increment fields in MS Access, specifically with issues that arise from using such code in the OnActivate event.
I have a field [Group_ID] that auto-increments each time a new record is made using custom code in the OnCurrent and OnActivate events. Sometimes I need Group_ID to be incremented OnActivate, but sometimes I do not. In some cases users will actually use a "duplicate record" button to use the same Group_ID (along with most other fields) for a subsequent record. In situations like these, I'd like to set a condition for the OnActivate event that allows users to reference other forms or tables without re-querying Group_ID upon returning to the form to finish a record. Here is my code:
'increments Group_ID when a new record is made
Private Sub Form_Current()
If Me.NewRecord = True Then
Me.Group_ID = Nz(DMax("Group_ID", "All_sightings"), 1) + 1
End If
End Sub
'increments Group_ID when the form becomes active IF the value is no
longer max value + 1
Private Sub Form_Activate()
If Me.Group_ID = Nz(DMax("Group_ID", "All_sightings")) + 1 Then
Else
Me.Requery
End If
End Sub
What I would like to do is add an additional condition to the Form_Activate sub that checks whether a different field is already filled out (e.g. if the "duplicate" button was used) when the form re-activates after a user returns to a partially completed record. This field will not require any input from the user because it will be automatically filled when a user clicks the duplicate button. The field I have chosen is [UTM_x].
I have tried:
=IIF(Me.Group_ID = Nz(DMax("Group_ID", "All_sightings")) + 1 And Not IsNull(Me.UTM_x), "", Me.Requery)
And various other combinations of nested IIF() and IfThenElse statements, but have not had any luck. The form continues to requery every time on the OnActivate event when Group_ID is not more than (max+1). Any suggestions?

Answer 1

I played around with iif statements and more if-then-else statements, eventually finding a solution to my problem. Here it is:
Private Sub Form_Activate()
If Me.Group_ID = Nz(DMax("Group_ID", "All_sightings")) + 1 Then
'blank/do nothing because Group_ID is already max+1
ElseIf IsNull(UTM_x) Then
Me.Requery 'makes Group_ID max+1 because null UTM_x means it's a new record
Else
'blank/do nothing because Group_ID = max and this is a duplicated record
End If
End Sub