title: Can not insert css image into pseudo :before
body: <p>I am trying to insert a background image into a header:before element, but jquery fails.</p>
  
  <p><strong>HTML</strong>
       
         content
       </p>
  
  <pre><code> &lt;a href="image.jpg" class="image-source"&gt;Try insert image into .header:before&lt;/a&gt;
  </code></pre>
  
  <p><strong>JS</strong></p>
  
  <pre><code> $('.image-source').click(function() {
     var src = $(this).attr('href');
      // slash is okay
      $('.header:before').css('backgroundImage', 'url(/' + src + ')'); 
      return false;
   });
  </code></pre>
  
  <p>CSS:</p>
  
  <pre><code>.header {
    position: relative;
    background: url(anotherimage.jpg) no-repeat;
  }
  .header:before  {
    position:absolute;
    top:0;
    left:0;
    right:0;
    bottom:0;
    margin:auto;
    min-width:50%;
    min-height:50%;
    content: "";
  }
  </code></pre>
  
  <p>Does anyone know if I am dealing with a bug here, or missed an obvious?
  Note, I can not use <code>.header</code> itself, because I am working with multiple background image, thats why I need <code>:before</code>.</p>
  
  <p><strong>UPDATE:</strong> 
  Might be this:</p>
  
  <ul>
  <li><p><a href="http://www.w3.org/TR/2009/CR-CSS2-20090908/generate.html#x2" rel="nofollow noreferrer">http://www.w3.org/TR/2009/CR-CSS2-20090908/generate.html#x2</a></p></li>
  <li><p><a href="https://stackoverflow.com/questions/5814810/target-before-and-after-pseudo-elements-with-jquery#comment6671974_5814824">Target :before and :after pseudo-elements with jQuery</a></p></li>
  </ul>