title: How to use JQuery .on() to catch the scroll event
body: <p>I'm attempting to use the .on() from jQuery to catch a scroll event that is inside a  tag.</p>
  
  <p>so this was my solution: </p>
  
  <ul>
  <li>the div id='popup'</li>
  <li>the .fixedHeader class is something I'm trying have fixed at the top of the div frame.</li>
  <li><p>getScrollTop() is a javascript function to return the top value (works)</p>
  
  <pre><code>$(document).on("scroll#popup", '#popup', function(){
     alert('scrolling');
     $(".fixedHeader").css("position", "relative");
     $(".fixedHeader").css("top", getScrollTop());
  });
  </code></pre></li>
  </ul>