网上下了一个ASP.NET的实例，打算自己研究研究的，可是运行的时候出现了错误，具体代码如下：
- C# code
<div id="topmenu"> <ul> <li id="one"><a href="Default.aspx" onmouseout="MM_showHideLayers('sub02','','hide')" onmouseover="MM_showHideLayers('sub02','','show')" title="新闻资讯">首页</a></li> <li id="two"><a href="NewsList.aspx" onmouseout="MM_showHideLayers('sub02','','hide')" onmouseover="MM_showHideLayers('sub02','','show')" title="新闻资讯">新闻资讯</a></li> <li id="eight"><a href="HotalList.aspx" onmouseout="MM_showHideLayers('sub09','','hide')" onmouseover="MM_showHideLayers('sub05','','show')" title="酒店信息">酒店信息</a></li> <li id="eight"><a href="JingdianList.aspx" onmouseout="MM_showHideLayers('sub10','','hide')" onmouseover="MM_showHideLayers('sub05','','show')" title="景点信息">景点信息</a></li> <li id="eight"><a href="TravelList.aspx" onmouseout="MM_showHideLayers('sub11','','hide')" onmouseover="MM_showHideLayers('sub05','','show')" title="旅行社信息">旅行社信息</a></li> <%--<li id="six"><a href="liuyan.aspx" onmouseout="MM_showHideLayers('sub06','','hide')" onmouseover="MM_showHideLayers('sub06','','show')" title="留言中心">留言中心</a></-li>--%> <li id="seven"><a href="XianluList.aspx" onmouseout="MM_showHideLayers('sub07','','hide')" onmouseover="MM_showHideLayers('sub07','','show')" title="线路信息">线路信息</a></li> <li id="eight"><a href="liuyan.aspx" onmouseout="MM_showHideLayers('sub08','','hide')" onmouseover="MM_showHideLayers('sub08','','show')" title="留言中心">留言中心</a></li> <li id="eight"><a href="Register.aspx" onmouseout="MM_showHideLayers('sub08','','hide')" onmouseover="MM_showHideLayers('sub08','','show')" title="用户注册">用户注册</a></li> <li id="eight"><a href="login.aspx" onmouseout="MM_showHideLayers('sub08','','hide')" onmouseover="MM_showHideLayers('sub08','','show')" title="用户登录">用户登录</a></li> </ul> </div>错误提示是：MM_showHideLayers 未定义！
求大神帮助，只为理解
------解决方案--------------------------------------------------------
MM_showHideLayers
找下在哪个文件中的，把它包含进去
------解决方案--------------------------------------------------------
没有实现MM_showHideLayers方法，肯定是抄来的代码