Dropdown List selection action checks cell value

Hi,

I have multiple dropdown list created from data validation. When a user selects value in dropdown list there are two cells (G9 and E8) down below in the table, I want to check those cell values. And I do not know how to link this method to dropdown list.

I have:
Private Sub dropdown2_Change(ByVal Target As Range)
If Range("G9").Value > Range("E8").Value Then alert ("Warning")
End If
End Sub

Your help will be really appreciated.

Thanks.