VS 2008 Function with Optional array

Public Sub Fill_Combo_Bound(ByVal Cbo As ComboBox, _
                                ByVal SQL As String, _
                                ByVal DisplayField As String, _
                                 ByVal ValueField As String, _
                                Optional ByVal At_Param() As String = Nothing, _
                                Optional ByVal At_values() As String = Nothing)
 
end sub