title: setInterval/setTimeout return value
body: <p>Two questions:</p>
  
  <ol>
  <li><p>How is the value returned from <code>setInterval</code> and <code>setTimeout</code> (the ones used to clear the timers) calculated?</p></li>
  <li><p>Is it possible for both the functions to return the same value during runtime?
  For example:</p>
  
  <p><code>var a = setInterval(fn1, 1000);</code><br>
  <code>var b = setTimeout(fn2, 1000);</code></p></li>
  </ol>
  
  <p>Is it possible for <code>a</code> and <code>b</code> to have the same value?</p>
  
  <p>The first one is more of a for-my-knowledge question, but the second one is more important.</p>