title: Browser behavior after location.replace
body: <p>I'm writing a piece of code that fires multiple image calls (pixels) and sometimes these calls can be latent based on server availability. I've devised a call where if all the calls aren't completed within 5 seconds, the page gets redirected via location.replace to an empty HTML page.</p>
  
  <p>The whole thing is wrapped inside an iFrame and when i test it in Firebug, it seems to work well. When i look at the call in Fiddler, the time is shown as the full time the server took to reply (even though the browser was no longer waiting for the call).</p>
  
  <p>What exactly is happening in the browser? Is it free to continue doing anything else it needs to? is it really still waiting for the call to come back even though the iframe has been changed via location.replace?</p>
  
  <p>Let's assume this is the code in an iFrame, and the iFrame is placed on another page.</p>
  
  <pre><code>&lt;html&gt;
  &lt;body&gt;
      &lt;img src="http://localhost:8080/MyServer/MyFirstCall" width="1" height="1"/&gt;
      &lt;img src="http://localhost:8080/MyServer/MySecondCall" width="1" height="1"/&gt;
      &lt;script&gt;
          window.setTimeout("if(true) {location.replace('http://somewhere/empty.html');}", 5000);
      &lt;/script&gt;
  &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>Firebug will tell me that everything is OK and the empty.html is loaded (of course i'm on debug and forcing the calls to be return after 5 seconds).</p>
  
  <p>Fiddler on the other hand will tell me that the Overall Lapsed time on the FirstCall or SecondCall was 30seconds (or whenever i decided to let the debugger go).</p>
  
  <p>Is the browser really waiting? Is it not waiting and is Fiddler just too smart and keeps track of calls even when they are no longer valid? Will other content continue to run or will the browser hold up the other things because the call hasn't technically returned?</p>