title: On scroll change opacity of header?
body: <p>Im so new to JQuery and im sure the answer is super basic. But if someone can point me in the right direction that would be great. I just want the opacity of my header to change from 0 to 1 as the user scrolls past 400 pixels. HELP? www.HULU.com has a perfect example.</p>
  
  <pre><code>&lt;code&gt;
  &lt;script&gt;
  $(document).ready(function() {
          $(window).scroll(function() {
              if ($(this).scrollTop() &gt; 400) {
                  $('.header').css("background", "#000");
              } else {
                  $('.header').css("background", "transparent");
              }
          });
          });
  &lt;/script&gt;
  &lt;/code&gt;
  </code></pre>