"use strict"; $(document).ready( () => { // preload images $("#image_list a").each( (index, link) => { const image = new Image(); image.src = link.href; }); // set up event handlers for links $("#image_list a").click( evt => { // get clicked tag const link = evt.currentTarget; // swap image $("#main_image").attr("src", link.href); //swap caption $("#caption").text(link.title); // cancel the default action of the link evt.preventDefault(); }); // move focus to first thumbnail $("li:first-child a").focus(); });