mar = new MarchePersistantImpl(nbMar);
pm.makePersistent(mar);
nbMar ++;
}
if ((idArt % 2) == 0) { //pair
a = new ServicePersistantImpl(idArt);
a.setNom("article_service_" + idArt);
} else { //impair
a = new MaterielPersistantImpl(idArt);
a.setNom("article_materiel_" + idArt);
}