title: Cross-domain window.close event from parent window
body: <p>For example I'm on domain1:</p>
  <pre><code>a.click(function(){
    window.win=window.open(domain2,'name');
  });
  </code></pre>
  <p>Now I'm on domain2 and I'm closing it. How will <code>window.win</code>  know that user closed that window? Is there any event or property to check via interval?</p>