una/template/menu_main.html

<ul id="bx-menu-main" class="bx-menu-main bx-def-font-h3">
    <bx_repeat:menu_items>
        <li class="__class_add__"><a class="bx-def-padding-right bx-def-padding-left" href="__link__" target="__target__" onclick="__onclick__">__title__</a></li>
    </bx_repeat:menu_items>
    <div class="bx-clear"></div>
</ul>
<script>
    $(document).ready(function () {
        $('#bx-menu-main li').click(function () {
            $('#bx-menu-main li').removeClass('bx-menu-tab-active');
            $(this).addClass('bx-menu-tab-active');
        });
    });
</script>