I need some help with CSS. I am trying to create a tree with lots of <ul> and <li> tags. The problem is that I have many <li> tags with a particular class, and inside that list I have an <img> tag. 
How can I access that <img> tag and put different background image? I am confused how to point my <img> tag with the class of the <li> and then set a background-image.
Note: CSS3 is not allowed
<ul>
  <li class="leaf"><img></li>
  <li class="leafhidden"><img></li>
  <li class="leafhidden"><img></li>
</ul>
Thank You
 
     
     
     
    