Given
<ul class="menu">
<li> <!-- layer1 -->
<a href="/gbcweb/index.php?option=com_content&view=article&id=19&Itemid=27">
<span>sub menu</span>
</a>
<ul>
<li><!-- layer2 -->
<a href="/gbcweb/index.php?option=com_content&view=article&id=22&Itemid=34">
<span>sub menu1</span>
</a>
<ul>
<li><!-- layer3 -->
<a href="/gbcweb/index.php?option=com_content&view=article&id=22&Itemid=34">
<span>sub menu2</span>
</a>
<!-- Continue layering -->
</li>
</ul>
</li>
</ul>
</li><ul>
How do I select all the from layer 2 onwards?And set a background image to all sub menu.