Private Sub Worksheet_Change(ByVal Target As Range)
If Not Intersect(Range("monchamp"), Target) Is Nothing And Target.Count = 1 Then
For Each c In Range("monchamp")
If UCase(c.Value) = UCase(Target.Value) And c.Row <> Target.Row And c.Value <> Empty Then
réponse = MsgBox("Doublon en :" & c.Address & Chr$(10) & _
"Voulez-vous le garder ?", vbYesNo + vbInformation, "DETECTION DOUBLON")
If réponse = vbNo Then
Application.EnableEvents = False
Target.Value = Empty
Target.Select
Application.EnableEvents = True
End If
End If
Next c
End If
End Sub