{% load parameters %}
<span class="filter-model sort-values sort">
    <a class="flat-button  {% if sorting_down %}current{%endif%}" title="Click to sort in descending order" href="{% url filter_url %}?{% parameters sort='on' field=down_field %}"><i class="fa fa-sort-desc"></i></a><a class="flat-button  {% if sorting_up %}current{%endif%}" title="Click to sort in ascending order" href="{% url filter_url %}?{% parameters sort='on' field=up_field %}"><i class="fa fa-sort-asc"></i></a>
</span>