protected void onSubmitForm() {
   String valueName = HtmlSanitizer.sanitize(modelName.getObject());
   Collection<UserRoles> newRoles = modelRoles.getObject();
   _user.setName(valueName);
   String password = modelPassword1.getObject();
   try {
     facade.createIdentity(selectedProvider, valueName, password, null, newRoles);
     setResponsePage(UserOverviewPage.class);
   } catch (UserExistsException e) {
     error(e.getMessage());
   }
 }