Private Sub Worksheet_Change(ByVal Target As Range)
Dim i As Integer
Dim c As Range
If Not Intersect(Target, Range("B4:K33")) Is Nothing Then
i = Target.Row
For Each c In Range("B" & i & ":K" & i)
If Not c.Address = Target.Address Then
If c.Value = Target.Value Then
MsgBox "OUPS, Déjas pris !!!"
Target.ClearContents
End If
End If
Next
End If
End Sub