Private Sub Worksheet_Change(ByVal Target As Range)
If Target.Count > 1 Then Exit Sub
If Target <> "" Then
If Target.Column = 2 And Target.Row > 16 Then
With Target.Offset(, 1).Validation
.Delete
.Add Type:=xlValidateList, AlertStyle:=xlValidAlertStop, Operator:= _
xlBetween, Formula1:="=" & Target
End With
End If
End If
End Sub