easyui layout遮挡导航菜单下拉框
如题，我把导航条放入了easyui latout north中，但导航条中的下拉菜单不能漂浮出div层，发现原因就是加了region=“north”，该怎么解决？
layout布局的容器都增加了overflow:hidden，超出范围就会被隐藏，要单独给north版块容器设置overflow auto
$(function(){
//注意如果layout容器不是body修改选择器
$(document.body).layout('panel','north').parent().css('overflow','auto')
});
上代码放到easyui框架下，不能放前面，同时你的z-index要设置大一些，至少10以上
<body class="easyui-layout">
<!-- header -->
<div class="header_full w_100" region="north" >
<script>
$(function () {
//注意如果layout容器不是body修改选择器
$(document.body).layout('panel', 'north').parent().css('overflow', 'auto');
});
</script>
<div class="header">
<!-- top_left | logo -->
<div class="logo f_l"> </div>
<!-- top_right -->
<div class="top_right f_r">
<!-- menu -->
<div class="nav_bar">
<ul class="nav clearfix">
<!-- 单一菜单 | end -->
<li class="m">
<h3><a href="#" >首页</a></h3>
</li>
<li class="s">|</li>
<li class="m">
<h3><a target="_blank" href="#">查询统计</a></h3>
<ul class="sub">
<li ><a href="#">设备查询</a> </li>
</ul>
</li>
<li class="s">|</li>
<li class="m">
<h3><a target="_blank" href="#" >基础数据</a></h3>
<ul class="sub">
<li ><a href="#">设备添加</a> </li>
<li ><a href="#">设备绑定</a> </li>
</ul>
</li>
<li class="block"></li><!-- 滑动块 -->
</ul>
</div>
<!-- menu | end -->
</div>
</div>
</div>
<!-- header | end -->
<div region="center" style="width:200px">sadaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa</div>
</body>
.header_full{height:47px; border-bottom:1px solid #51AACA;}
.header{width:x;}
/* left */
.logo{width:210px; padding-top:27px; padding-left:66px;}
.logo360{width:81px; padding-top:27px;}
/* right */
.top_right{width:748px;}
/* top_link */
.top_link{padding-top:24px; height:26px; line-height:26px; padding-right:35px; text-align:right;}
.top_link i{color:#686868;}
.top_link span,.top_link a{color:#46AAFE;}
.top_link a{font-size:13px;}
.top_link a:hover{text-decoration:underline;}
/* nav */
.clearfix:after{content:".";display:block;height:0;clear:both;visibility:hidden;}
.nav_bar{position:relative; z-index:999; height:32px; line-height:42px; color:#333;padding-top:5px;}
.nav{position:relative; width:748px; margin:0 auto; font-family:"Microsoft YaHei",SimSun,SimHei; font-size:14px;}
.nav a{color:#333;}
.nav h3{font-size:100%; font-weight:normal;}
.nav h3 a{display:block; width:120px; text-align:center; font-size:14px;}
.nav .m{float:left; position:relative; z-index:1;}
.nav .s{float:left; width:3px; text-align:center; color:#D4D4D4; font-size:12px;}
.nav .sub{display:none; position:absolute; left:-3px; top:42px; z-index:999; width:128px; border:1px solid #E6E4E3; border-top:0; background:#fff;}
.nav .sub li{text-align:center; padding:0 8px; margin-bottom:-1px;}
.nav .sub li a{display:block; border-bottom:1px solid #E6E4E3; padding:8px 0; height:28px; line-height:28px; color:#666;}
.nav .sub li a:hover{color:#1E95FB;cursor:pointer;}
.nav .block{height:3px; width:126px; background:#1E95FB; position:absolute; left:0; top:39px; overflow:hidden;}
/* 重用类样式 */
.f_l{float:left !important;}
.f_r{float:right !important;}
.no_margin{margin:0px !important;}
.no_border{border:0px !important;}
.no_bg{background:none !important;}
.clear_both{clear:both !important;}
.display_block{display:block !important;}
.text_over{overflow:hidden; white-space:nowrap; text-overflow:ellipsis; -o-text-overflow:ellipsis; -moz-binding: url('ellipsis.xml#ellipsis');}
/* 重用自定义样式 */
.w_100{width:100%;}
.w_95{width:95%;}
.indextx{width:980px;margin:0 auto; margin-top:10px; background:#FFFFFF;}
.w_min_width{min-width:1200px;}
.w_1200{width:1200px;}
.w_1067{width:1067px;}
.w_980{width:980px;}
求大神帮忙再看看，我这里还是不行。而且我这里最后显示效果如下图
是有scrolling的，好像不是overflow:hidden吧，麻烦您了