Private Sub Worksheet_Change(ByVal Cible As Range)
Dim d As Date, x As Range, y As Range, z As Range
d = DateSerial(2012, 1, 1)
Set x = Range("C8")
Set y = Range("B10")
Set z = Range("D11,F11")
If Not Intersect(Cible, Union(x, y)) Is Nothing Then
If IsDate(x.Value) Or IsEmpty(x) Then
Application.EnableEvents = False
If x.Value < d Then Union(y, z) = Empty Else If Not Intersect(Cible, y) Is Nothing Then If y.Value <> "x" Then z = Empty
Application.EnableEvents = True
End If
End If
End Sub