Private Sub NomVehiculeBox_Exit(ByVal Cancel As MSForms.ReturnBoolean)
For Each c In [Nom_vehicule]
If Trim(c) = Trim(NomVehiculeBox.Value) Then
MsgBox c & vbLf & "Ce véhicule est déjà en service", , "Doublon": NomVehiculeBox = "": Cancel = True: Exit For
End If
Next
End Sub