First of all, you shouldn't use special characters like ? in field or control names
Add code to the After_Update event for your invoice field
If you just want to move to the Paid control then something like:
Code:
Private Sub InvoiceNumber_AfterUpdate()
If Me.InvoiceNumber<>"" Then
Me.[Paid?].SetFocus
End If
End Sub
If you want to populate the field then perhaps this would work:
Code:
Private Sub InvoiceNumber_AfterUpdate()
If Me.InvoiceNumber<>"" Then
Me.[Paid?] = "Paid"
Else
Me.[Paid?] = ""
End If
Me.Requery 'update display
End Sub
Modify all names to suit your control names