DIV结构的点击收缩展开左边栏代码(html+css+js)

DIV结构的点击收缩展开左边栏，右栏可100%显示。HTML+css+js结构，结构清晰明了，部分结构代码如下：

<div class="main">
  <div class="main_left" id="frmTitle" name="fmTitle" > 左边</div>
  <div class="picBox" onclick="switchSysBar()" id="switchPoint" ></div>
  <div class="main_right">
        <ol>
            <li><a href="http://www.51xuediannao.com/JS/nav/">CSS导航菜单</a></li>
            <li><a href="http://www.51xuediannao.com/JS/Slide/">FLASH焦点图</a></li>
            <li><a href="http://www.51xuediannao.com/JS/texiao/">网页特效JS</a></li>
            <li><a href="http://www.51xuediannao.com/JS/AD/">JS广告代码</a></li>
            <li><a href="http://www.51xuediannao.com/jiqiao/html/">HTML技巧</a></li>
            <li><a href="http://www.51xuediannao.com/jiqiao/css/">CSS技巧</a></li>
            <li><a href="http://www.51xuediannao.com/jiqiao/cms/">CMS建站技巧</a></li>
            <li><a href="http://www.51xuediannao.com/jiqiao/qita/">其他技巧</a></li>
        </ol>
  </div>
</div>