title: Change the background image of a div depending on which link is selected in the navigation
body: <p>i'd like to change the background image of a div depending on wich link is selected in my navigation!</p>
  
  <p>exemple : 
  let's say I have a menu item called : </p>
  
  <pre><code>#nav li.menu-item-59
  </code></pre>
  
  <p>when the link is selected it changes to </p>
  
  <pre><code>#nav li.menu-item-59.selected a
  </code></pre>
  
  <p>I'd like that whenever one of the menu item is selected the background image of the div footer change to a different file...</p>
  
  <p>I've read some articles about sibling operators but can't seem to make it work and I'm not sure it is the best way to go ..
  can anyone help?
  thanks ! :D</p>