dot.js spider checking a site for broken images

spider.js

function advance() {
  var url = document.location.href;
  var parts = url.split('/');
  var id = parts[parts.length-1];
  var nextID = parseInt(id) + 1;
  document.location = "https://site.com/resources/" + nextID;
}

var image = $('img.should-be-here');

if (!image.length) advance();

image.load(function() {
  setTimeout(advance, 1000);
});

$(document).click(advance);