title: window.open.. A way to tell if the window had a timeout or 404?
body: <p>I've been making a webpage that uses a sort of... external survey taking. I was wonder if when using the window.open method, can you tell if your new window had a 404 or the page timedout trying to load?</p>
  
  <p>Here is what I have so far:</p>
  
  <pre><code>child = window.open(href, 'window');
          setTimeout(function() {
              // Do some backend processing if child window is still open and no 404 / timeout
          }, 10000);
  </code></pre>