title: jQuery .toggleClass() does not toggle off the class after its toggled on
body: <p>In order to change the color scheme of the site, I've added an alternate class that was suppose to toggle on and off through a button with the usage of <code>.toggleClass()</code>, however, when I do toggle the class on, it doesn't seem to toggle back off when I click on the button again.</p>
  
  <p>CSS</p>
  
  <pre><code>/*
  Alternate color (dark) scheme
  */
   body.dark {
      background-color:#1e1d1b;
  }
  body.dark #main {
      background:#292826 url(background_dark_slice.jpg) repeat-x;
  }
  body.dark #main .container {
      background-image:url(background_dark.jpg);
  }
  body.dark #footer {
      background-image:url(background_dark_footer.jpg);
  }
  body.dark ul#menu li a.active, ul#menu li a:hover {
      color:#ffffff;
  }
  </code></pre>
  
  <p>jQuery</p>
  
  <pre><code>$(document).ready(function(){
      var button = document.querySelector('.forjs button');
      button.addEventListener('click', function(){
          $('.dark').toggleClass();
      });
    });
  
  </code></pre>