{% if main_menu.get_top_level %}
    <nav class="navigation navbar navbar-default">
        <div class="menu navbar-collapse collapse">
            <ul class="top_level nav navbar-nav">
                {% for nav_item in main_menu.get_top_level %}
                    <li class="{% if forloop.last %}last{% endif %}"><a href="{{ nav_item.url }}">{{ nav_item.name }}</a></li>
                {% endfor %}
            </ul>
            <div class="clear"></div>
        </div>
    </nav>
{% endif %}