title: jQuery 'scroll' not firing
body: <p>I have the following:</p>
  
  <pre><code> var onScroll = function () {
          alert('scroll');
   };
   scrollArea = $('body');
   scrollArea.on('scroll', onScroll);
  </code></pre>
  
  <p>I can do <code>$('body').scrollTop(400)</code> and the body scrolls fine, but the <code>alert</code> is never called when I manually scroll.  What could be causing this?</p>