Private Sub Worksheet_Change(ByVal Target As Range)
Dim Cellule As Range
Dim EnableEventsAtCallTime As Boolean
EnableEventsAtCallTime = Application.EnableEvents
Application.EnableEvents = False
With ThisWorkbook.Worksheets("Validation")
For Each Cellule In Target.Cells
if Not IsEmpty(.Cells(Cellule.Row, 13)) then .Cells(Cellule.Row, 13).ClearContents
Next Cellule
End With
Application.EnableEvents = EnableEventsAtCallTime
End Sub