'Fonction qui permet de vérifier la présence de la future nouvelle feuille
If WsExist(num_new_family) = True Then
MsgBox ("the family " & num_new_family & " already exists.")
Select Case MsgBox("Do you want to copy all the data of family " & num_old_family & " to Family " & num_new_family & " and overwrite the data of this family ?", vbYesNo + vbQuestion + vbDefaultButton2, "Comparison")
Case vbYes
GoTo line_deb_split
Case vbNo
Exit Sub
End Select
Else: MsgBox ("la famille n'existe pas" & num_new_family)
End If