关于AJAX安插事件后改变CSS没反应

<form id="form1" runat="server">

    <div class="head">

        <span class="logo">

            <img src="/images/logo.png" />

        </span>

        <span>

            <img src="/images/men.png" />

        </span>

        <span class="men">

            欢迎您登录 | 

        </span>

        <div id="outbtn" class="headbotton">

            <img src="/images/out.png" title="退出" />

        </div>

        <div id="helpbtn" class="headbotton">

            <img src="/images/help.png" title="帮助" />

        </div>

        <div id="systembtn" class="headbotton">

            <img src="/images/system.png" title="系统设置" />

        </div>

    </div>

    <div id="menu" class="menu">

        <span id="grzxMenu">个人中心</span>

        <span id="sdnmMenu">失地农民</span>

        <span id="qyglMenu">企业管理</span>

        <span id="zpxxMenu">招聘信息</span>

        <span id="pxMenu">培训</span>

        <span id="xxcxMenu">信息查询</span>

        <span id="glyglMenu">管理员管理</span>

        <span id="dxshMenu">短信审核</span>

        <span id="xtszMenu">系统设置</span>

    </div>

    <div class="menusmall">

        <div id="grzx" style="display:block;">