Problème Jquery

<script type="text/javascript"> 
    $(document).ready(function(){ 
							   
	 $("#btn").css({'background' : ' url(images/btn1.jpg) 0 0'});
	 
	 $("#btn").click(function () {
										 
		 if ($("#bar").is(":hidden")) {
		 $("#btn").animate({ bottom: "47px"},
                 {duration: 500,});
		 $("#btn").css({'background' : 'url(images/btn1.jpg) 0 -45px' });
		 $("#bar").slideDown("normal");
	 return false;
	 
			  }else {
				  
		$("#btn").animate({ bottom: "0"},
               {duration: 600, easing: 'easeOutBounce',});
	       $("#btn").css({'background' : 'url(images/btn1.jpg) 0 0'});
               $("#bar").slideUp("normal", "easeOutBounce")};
	   return false;
	});	
    }); 
</script>