title: jQuery find when user scrolled out an element
body: <p>I have 2 <code>divs</code>:</p>
  
  <pre><code>&lt;div id="div1"&gt;&lt;/div&gt;
  &lt;div id="div2"&gt;&lt;/div&gt;
  </code></pre>
  
  <p>I would like to add <code>css({'position':'relative'})</code> to div2 ONLY when a user scrolls the page and div1 is no longer visible on the page. When div1 is visible again, I want to remove the css rule.</p>
  
  <p>Can anyone help me?</p>