Test if an image does NOT load

image-not-loaded.js

// From: http://jsfiddle.net/jfriend00/qKtra/ & http://stackoverflow.com/questions/9714525/javascript-image-url-verify/9714891#9714891
function testImage(url, callback, timeout) {
  timeout = timeout || 5000;
  var timedOut = false, timer;
  var img = new Image();
  img.onerror = img.onabort = function() {
      if (!timedOut) {
          clearTimeout(timer);
          callback(url, "error");
      }
  };
  img.onload = function() {
      if (!timedOut) {
          clearTimeout(timer);
          callback(url, "success");
      }
  };
  img.src = url;
  timer = setTimeout(function() {
      timedOut = true;
      callback(url, "timeout");
  }, timeout); 
}