title: onload js function is not working in chrome extension
body: <p>I wrote a clock function in js, this function is need to start when the body is loaded ("onload"). The function is working basically without any problem.
  But when I run the code with html as a Chrome extension the function is not running.</p>
  
  <p>This is the clock function:</p>
  
  <pre><code>function startTime() {
  var today = new Date();
  var h = today.getHours();
  var m = today.getMinutes();
  var s = today.getSeconds();
  m = checkTime(m);
  s = checkTime(s);
  document.getElementById('clock').innerHTML =
  h + " : " + m ;
  var t = setTimeout(startTime, 500);
  }
  function checkTime(i) {
      if (i &lt; 10) {i = "0" + i};  
      return i;
  }
  </code></pre>
  
  <p>And this is the html</p>
  
  <pre><code>&lt;body onload="startTime()"&gt;
  
  
      &lt;script src="clockTime.js" type="text/javascript"&gt;&lt;/script&gt;
  
  
          &lt;div class="clockTimeBox" id="clock"&gt;
  
          &lt;/div&gt;
  
  &lt;/body&gt;
  </code></pre>
  
  <p>Maybe I need to add something to the manifest?</p>