Private Sub Worksheet_Change(ByVal Target As Range)
If Not Intersect(Target, [A1]) Is Nothing And CStr([A1]) <> "" Then [A2] = ""
If Not Intersect(Target, [A2]) Is Nothing And CStr([A2]) <> "" Then [A1] = ""
ScrollArea = IIf(Application.CountA([A1:A2]) = 1, "", "A1:A2")
End Sub