var MiniGallery = {
    setup: function() {
        $$('#product_gallery_thumbnail_row .thumbnail').each(function(thumbnail) {
            thumbnail.observe('click', function(the_click) {
                MiniGallery.change_main_image(the_click, thumbnail);
            });
        });
    },
    
    change_main_image: function(the_click, thumbnail) {
        var main_image = $('product_gallery_main_image');
        var main_image_link = $('product_gallery_main_image_link');
        
        if(main_image) {
            the_click.stop();
            main_image.src = thumbnail.href;
            main_image_link.href = thumbnail.href.replace(/\/large\//, '/originals/');
        }
    },
    
    get_full_image_link: function(image_url) {
        
    }
}

Event.observe(document, 'dom:loaded', MiniGallery.setup);