JQuery: Efeito SlideUp / SlideDown aplicado ao topo do site

<style type="text/css">
*{ 
 margin:0;
 padding:0;
 font-family:Arial, Helvetica, sans-serif;
 color:#000;
}
#containerTopo{ 
 position:fixed; 
 top:0; 
 width:100%; 
 color:#FFFFFF;
 border-bottom:4px solid #0099FF;
}
#topo{ 
 display:none;
 width:100%; 
 height:200px; 
 margin:0 auto;
 text-align:center;
 background-color:#0066CC;
 color:#FFFFFF;
}
#icone{ 
 position:absolute;
 bottom: -28px;
 right:5px;
 float:right;
 z-index:9999;
 height:24px;
 width:24px;
 cursor:pointer;
}
.plus{ background:url(plus.png) no-repeat; }
.minus{ background:url(minus.gif) no-repeat; }
#topo {
 background-color: #1E1B1A;
 padding: 25px 10px;
 height:60px;
}
.float{ float:left }
.clear{ clear:both }
#menu{ height: 80px; background-color:#003399; }
</style>

<style type="text/css"> *{ margin:0; padding:0; font-family:Arial, Helvetica, sans-serif; color:#000; } #containerTopo{ position:fixed; top:0; width:100%; color:#FFFFFF; border-bottom:4px solid #0099FF; } #topo{ display:none; width:100%; height:200px; margin:0 auto; text-align:center; background-color:#0066CC; color:#FFFFFF; } #icone{ position:absolute; bottom: -28px; right:5px; float:right; z-index:9999; height:24px; width:24px; cursor:pointer; } .plus{ background:url(plus.png) no-repeat; } .minus{ background:url(minus.gif) no-repeat; } #topo { background-color: #1E1B1A; padding: 25px 10px; height:60px; } .float{ float:left } .clear{ clear:both } #menu{ height: 80px; background-color:#003399; } </style>

<script type="text/javascript">
$(function() {
  $("#icone").click(function(){
     var topo 	= $("#topo");
     if (topo.is(":visible")){
	topo.slideUp( 500 );
	$("#icone").removeClass('minus').addClass('plus');
     } else {
	topo.slideDown( 500 );
	$("#icone").removeClass('plus').addClass('minus');
     }
  });
});
</script>

<script type="text/javascript"> $(function() { $("#icone").click(function(){ var topo = $("#topo"); if (topo.is(":visible")){ topo.slideUp( 500 ); $("#icone").removeClass('minus').addClass('plus'); } else { topo.slideDown( 500 ); $("#icone").removeClass('plus').addClass('minus'); } }); }); </script>

<div id="containerTopo">
    <div id="icone" class="plus"></div>
    <div id="topo">TOPO DO SITE</div>
</div>

<div id="containerTopo"> <div id="icone" class="plus"></div> <div id="topo">TOPO DO SITE</div> </div>