执行完JQuery hide()/show() @medio display属性失效

 1 <script>
 2     $(document).ready(function(){
 3         $("button").click(function(){
 4             if($(".itemright").attr("data-display")){
 5                 
 6                 $(".itemright").hide("fast",function(){$(".itemright").removeAttr("data-display");});
 7                 
 8             }else{
 9                 $(".itemright").attr("style","display:none");
10                 $(".itemright").show("fast",function(){
11                    $(".itemright").removeAttr("style");
12                 }).attr("data-display","1");
13                 
14             }
15             
16         });
17     });
18     
19     
20     </script>

<div class="bodymain">
<div class="hearder">头部div</div>
<div class="item">栏目div</div>

<div class="main">主体div</div>
<div class="itemright" data-display="1">
    <ul class="ul">
        <li><a href="http://www.baidu.com" target="_blank" class="a">aaa</a></li>

    </ul>
</div>
<div class="footer">底部div</div>
<div class="anniu"><button>button click</button></div>
</div>