Помогите с JS затемнение сайта

    <script type="text/javascript">
        $(document).ready(function(){
            $("#shadow").css("height", $(document).height()).hide();
            $(".lightSwitcher").click(function(){
                $("#shadow").toggle();
                if ($("#shadow").is(":hidden"))
                    $(this).html("Выключить свет").removeClass("turnedOff");
                 else
                    $(this).html("Включить свет").addClass("turnedOff");
            });
            
        });
    </script>

<a class="lightSwitcher">Выключить свет</a>

.lightSwitcher {position:absolute; z-index:101; background-image:url("../images/light_bulb_off.png"); background-repeat:no-repeat; background-position:left; padding: 0 0 0 20px; outline:none; text-decoration:none;}
.lightSwitcher:hover {color:#000088; text-decoration:underline;}
#shadow {background:#000000; opacity:0.96; filter:alpha(opacity=90); position:fixed; left:0; top:0; height:100%; width:100%; z-index:100; display:none;}
.turnedOff, .turnedOff2, .turnedOff3 {color:#ffff00; background-image:url("../images/light_bulb.png");}
.turnedOff:hover, .turnedOff2:hover, .turnedOff3:hover {color:#ffff00;}
object{
z-index:101;
position:relative;
}