jquery滑动门问题

Question

自己写了个滑动选项卡，代码如下，怎样改才能让当前点击的选项卡不能被再次点击<script type="text/javascript">
    $(document).ready(function(){
        $("#topmenu li").eq(0).addClass("bg");
        $("#contentin .content").eq(0).css("display","block");
        $("#topmenu li").each(function(index){
            if(index==4)
            {
                $("#topmenu li").eq(index).css('margin-right','0');
            }
            $(this).mouseover(function(){
                $("#topmenu li").removeClass("opea");
                $("#topmenu li").eq(index).addClass("opea");
            });
           var bin= $(this).click(function(){
                $("#topmenu li").eq(index).removeClass("opea");
                $("#topmenu li").removeClass("bg");
                $("#topmenu li").removeClass("bg1");
                $("#topmenu li").eq(index).addClass("bg");
                $("#contentin .content").hide("slow");
                $("#contentin .content").eq(index).show("slow");        });
    });
  });
    </script>
#topmenu .bg{
        background-image:url('images/topmenu_bg1.gif');
        color:white;
    }
    #topmenu .bg1
    {
       background-image:url('images/topmenu_bg2.gif');
       color:white; 
    }
    #middle{
        width:900px;
        height:326px;
        float:left;
    }
    #middle ul{
        list-style:none;
        height:40px;
        width:900px;
        margin:0;
        padding:0;
    }
    #middle ul li{
        list-style:none;
        margin:0;
        margin-right:5px;
        font-size:15px;
        padding:0;
        padding-top:10px;
        width:176px;
        text-align:center;
        float:left;
        display:block;
        cursor:pointer;
        background-image:url('images/topmenu_bg.gif');
        background-repeat:repeat-x;
        color:white;
        height:40px;
        vertical-align:middle;
        display:inline;
        
    }
    .clickbg1
    {
        background-color:#eeff33;
    }
    #middle #topmenu{
        width:900px;
        height:40px;
        float:left;
        
    }
    #contentin{
        width:900px;
        height:286px;
        float:left;
    }
    #middle .content{
        width:900px;
        height:286px;
        float:left;
         _margin-top:-10px;
        background-image:url('images/content_bg.gif');
        display:none;
    }
<div id="middle">
            <div id="topmenu">
                <ul>
                    <li class="bg">关于我们</li>
                    <li>商标注册</li>
                    <li>合作伙伴</li>
                    <li>法律法规</li>
                    <li>联系我们</li>
                </ul>
            </div>
            <div id="contentin">
                <div class="content">第一个
                </div>
                <div class="content">第二个
                </div>
                <div class="content">第三个
                </div>
                <div class="content">第四个
                </div>
                <div class="content">第五个
                </div>
            </div>
        </div>

Answer 1

    $(document).ready(function(){  
                $("#GridView1 tr").mouseover(function(){
                 $(this).addClass("over");}).mouseout(function(){ 
                 $(this).removeClass("over");}).click(function(){ 
                      $(this).addClass("alt");
                      $("#GridView1 tr").not(this).removeClass("alt")});    
        });
        
        function EditUser() { 
         $('#empID').addClass("redonly");
         $('#empID').attr("readonly","readonly"); 
//         $("#bb").hide();
         $("#AddInfo").hide(); 
         $("#EditInfo").show();
         $("#bb").show('slow');         $(event.srcElement.parentElement.parentElement).find("td").each(function(i) {
             $("#sj>input").eq(i).val($(this).text());
             document.getElementById('empID').value = document.getElementById('Text1').value;
             document.getElementById('name').value = document.getElementById('Text2').value;
             document.getElementById('txtsex').value = document.getElementById('Text3').value;
             var doctorName = document.getElementById('Text4').value;
             var hisid = document.getElementById('Text5');
         });

Answer 2

谢谢大家，问题已经解决，js代码修改如下(红色部分)<script type="text/javascript">
    $(document).ready(function(){
        $("#topmenu li").eq(0).addClass("bg");
        $("#contentin .content").eq(0).css("display","block");
        $("#topmenu li").each(function(index){
            if(index==4)
            {
                $("#topmenu li").eq(index).css('margin-right','0');
            }
            $(this).mouseover(function(){
                $("#topmenu li").removeClass("opea");
                $("#topmenu li").eq(index).addClass("opea");
            });
           $(this).click(function(){
               if (!$(this).hasClass('bg'))
                {
                $("#topmenu li").eq(index).removeClass("opea");
                $("#topmenu li").removeClass("bg");
                $("#topmenu li").removeClass("bg1");
                $("#topmenu li").eq(index).addClass("bg");
                $("#contentin .content").hide("slow");
                $("#contentin .content").eq(index).show("slow");
                }
        });
    });
  });
    </script>