<ul class="mobile">
    <li class="liNews"><a href="#news" class="fw400">News</a></li>
    <li><a href="#info" class="fw400">Info</a></li>
    <li><a href="#classes" class="fw400">Classes</a></li>
    <li><a href="#contact" class="fw400">Contact</a></li>
</ul>

<div class="column sm4 accordion">
    <h3 id="boulder" class="ffHeavy">Boulder<span class="ffLight">Classes</span></h3>
    <div class="column accordionContent accordionBoulder">

       <!-- content -->

    </div><!-- accordionContent -->
</div><!-- accordion -->

$('.accordion h3').click(function() {
$('#kurse').removeClass('kidsclasses groupclasses otherclasses boulderclasses');
if ($(this).hasClass('active')) {
  $(this).parent().removeClass('active');
  $(this).removeClass('active');
}
else {
    $('.accordion').removeClass('active');
    $('.accordion h3').removeClass('active');
    $(this).parent().addClass('active');
    $(this).addClass('active');

    /* .... */
    }
 });