@Override
 public void backValuePlatform() {
   int index = platformValueListBox.getIndex();
   int size = platformValueListBox.getListSize();
   platformValueListBox.setFocus(false);
   if (index - 1 > 0) {
     platformValueListBox.setIndex(index - 1);
     arrowStatus(index - 1, size);
     Platform platform = platformValueListBox.getValue();
     presenter.getEventBus().searchForArticlePf(platform, false);
     lastPlatformChoice = platform;
   }
 }
 @Override
 public void backValueArticle() {
   int index = articlePfValueListBox.getIndex();
   int size = articlePfValueListBox.getListSize();
   articlePfValueListBox.setFocus(false);
   if (index - 1 > 0) {
     articlePfValueListBox.setIndex(index - 1);
     arrowStatus(index - 1, size);
     ArticlePf article = articlePfValueListBox.getValue();
     presenter.getEventBus().searchForStock(article, false);
     lastArticleChoice = article;
     presenter.setParamSessionArticlePf(article);
   }
 }