How do I make a sliding banner loop?

How do I make a sliding banner loop?

Hi, does any one know how I can make my sliding banner loop so that on the last slide it carries onto slide 1 again, instead of flicking backwards through the whole thing?

Here is my code

    $(function() {
            $('#banner').unslider();
        });
    var unslider = $('#banner').unslider();
    $('.unslider-arrow').click(function() {
        var fn = this.className.split(' ')[1];
        //  Either do unslider.data('unslider').next() or .prev() depending on the className
        unslider.data('unslider')[fn]();
    });