HTML:
   <ul id="knowledgemenu" class="x-hidden mymenu">
      <li><a id="knowledge"  class="menubar">知识导航</a></li>
      <li><a id="bbs"    class="menubar">公告</a></li>
      <li><a id="question"    class="menubar">待解决问题</a></li>
      <li><a id="sloved"    class="menubar">已解决问题</a></li>
      <li><a id="knownw"   class="menubar">知识贡献</a></li>
      <li><a id="tagslist"    class="menubar">Tags</a></li>
    </ul>
    <ul id="libmenu" class="x-hidden mymenu">
      <li><a id="knownlist"  class="menubar">文章库</a></li>
      <li><a id="booklist"  class="menubar">图书库</a></li>
      <li><a id="A1"  class="menubar">软件库</a></li>
    </ul>
CSS:

.menubar {
 border-bottom: 1px solid #AACCF6;
 color: #222222;
 cursor: pointer;
 display: block;
 height: 20px;
 width: 50px;
 line-height: 17px;
 outline-color: -moz-use-text-color;
 outline-style: none;
 outline-width: 0;
 padding: 3px;
 text-align: center;
 text-decoration: none;
 white-space: nowrap;
}

.menubar:hover {     //鼠标悬停上时触发
 background: #EBF3FD url(../item-over.gif) repeat-x scroll left bottom;
 text-decoration: none;
}

JS:
    var knowledgemenu = new Ext.Panel({
                 title: '翰维知道',
                 contentEl:'knowledgemenu',  //DOM标签ID
                 border:false,
                    iconCls:'nav'
                });
    var libmenu = new Ext.Panel({
                 title: '专题',
                 contentEl:'libmenu',
                 border:false,
                    iconCls:'nav'
                });
    var westPanel=new Ext.Panel({
                    region:'west',
                    el:'west',
                    title:'功能菜单',
                    collapsible: true,    //本窗口伸缩
                    //collapseMode:'mini',
                    split:true,
                    width: 175,
                    minSize: 175,
                    maxSize: 175,
                    margins:{left: 10, top: 0, right: 0, bottom: 0},
                    layout:'accordion',   //子窗口为折叠
                    layoutConfig:{
                        animate:true
                       // fill :false
                    },
                    items:[knowledgemenu, libmenu]
    });