<html> <head> <script type="text/javascript" src="js/jquery-1.3.2.js"></script> <script type="text/javascript"> $(document).ready(function(){ $("div").children().css("border-bottom", "3px double red"); }); </script> </head> <body> <body> <div id="container"> <div> asdf </div> </div> </body> </html>