title: How to start and stop/pause setInterval?
body: <p>I'm trying to pause and then play a <code>setInterval</code> loop.</p>
  
  <p>After I have stopped the loop, the "start" button in <a href="http://jsfiddle.net/Daniel_Hug/gEdKM/" rel="noreferrer">my attempt</a> doesn't seem to work :</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-js lang-js prettyprint-override"><code>input = document.getElementById("input");
  
  function start() {
    add = setInterval("input.value++", 1000);
  }
  start();</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;input type="number" id="input" /&gt;
  &lt;input type="button" onclick="clearInterval(add)" value="stop" /&gt;
  &lt;input type="button" onclick="start()" value="start" /&gt;</code></pre>
  </div>
  </div>
  </p>
  
  <p>Is there a working way to do this?</p>