this.add(new Label("personne.nom"));
this.add(new Label("personne.prenom"));
final DropDownChoice categorieChoice = new DropDownChoice(
"categorie", categorieService.list(),
new CategorieChoiceRenderer());
categorieChoice.setRequired(true);
categorieChoice.setEnabled(isNew);
this.add(categorieChoice);
final RequiredTextField plaque = new RequiredTextField(