title: Rails 3.1 using images under app/assets/images/subdirectory
body: <p>In my Rails 3.1 app, I have images stored under <code>app/assets/images/jquery_ui/</code>.</p>
  
  <p>I don't know how to access these in my CSS. <code>/assets/image_name.png</code> and <code>/assets/jquery_ui/image_name.png</code> do not work.</p>