XL 2010 message box si quantité atteinte

Sub Worksheet_Change(ByVal Target As Range)
    If Target.Count > 1 Then Exit Sub
    If Not Intersect(Target, Range("B3:B33")) Is Nothing Then
        If Application.Sum(Range("B3:B33")) >= Range("B1") Then
            MsgBox Application.Sum(Range("B3:B33")) & " poulets ont été vendus" & Chr(10) & "Le stock est vide"
        End If
    End If
End Sub