<html><head> <style> div { width:60px; height:60px; margin:10px; float:left; border:2px solid blue; } .blue { background:blue; } </style> <script type="text/javascript" src="/jquery/jquery.js"></script></head><body><ul> <li>list item 1</li> <li>list item 2</li> <li>list item 3</li> <li>list item 4</li> <li>list item 5</li></ul><script>$('li').eq(2).css('background-color', 'red');</script></body></html>