Untitled

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
    <html xmlns="http://www.w3.org/1999/xhtml">
    <head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
    <title>Exemplo</title>

    <style type="text/css">
    .focu {border:1px solid red;}
    </style>

    <script type="text/javascript" src="js/jquery-1.4.2.js"></script>
    <script type="text/javascript">

    $(document).ready (function(){

        $('.campo').focus(function(){
            $(this).toggleClass ('focu');
        });

        $('.campo').blur(function(){
            $(this).toggleClass ('focu');
        });

    })
    </script>
    </head>

    <body>
    <input type="text" name="nome" class="campo" />
    <br />
    <br />
    <textarea rows="10" cols="50" class="campo"></textarea>
    </body>
    </html>