<script type="text/javascript">

            $("a").click(function () {                clearClass();                $(this).addClass("bg_color");            });            function clearClass() {                $("a").each(function () {                    $(this).removeClass("bg_color");                });            }

        </script>

 <style type="text/css">        .bg_color        {            cursor:pointer;//鼠标显示效果，小手

            color:Red;

            font-weight:bold;//加粗

        }</style>