<div id="languages">
  <a {% if app.request.locale == 'fr' %}class="selected"{% endif %} href="{{ path('change_language', {'language' : 'fr'}) }}">FR</a>
  <a {% if app.request.locale == 'en' %}class="selected"{% endif %} href="{{ path('change_language', {'language' : 'en'}) }}">EN</a>
</div>