<script>
function Close1(){
var obj =document.getElementById("Slider").getElementsByTagName("div")
obj[2].style.display=(obj[2].style.display=="none"?"":"none")
}
</script>
<div id="Slider"> 
            <div id="Menu0"> 
                <div class="Header"> 
                    <span>系统任务 </span> 
                    <img name="headerimg" src="image/xpcollapse1_s.gif" alt="" onclick="Close1()" /> 
                </div> 
                <div class="Content"> 
                    <ul> 
                        <li> <a href="#" id="SysInfo"> <span>查看系统信息 </span> </a> </li> 
                        <li> <a href="#" id="SysUninstall"> <span>添加/删除程序 </span> </a> </li> 
                        <li> <a href="#" id="SysControl"> <span>更改一个设置 </span> </a> </li> 
                    </ul> 
                </div> 
            </div> 
没改变html的部分  但是你结尾的地方确实是掉了个</div>  不信你数数

解决方案 »

  1.   

    <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
    <HTML>
     <HEAD>
      <TITLE> New Document </TITLE>
      <script>
    function Close1()
    {
         var  divArr=window.event.srcElement.parentElement.parentElement.getElementsByTagName("div")
    ; divArr[1].style.display=(divArr[1].style.display=="none"?"":"none");

    }
      </script>
     </HEAD> <BODY>
      <div id="Slider"> 
                <div id="Menu0"> 
                    <div class="Header"> 
                        <span>系统任务 </span> 
                        <img name="headerimg" src="image/xpcollapse1_s.gif" alt="" onclick="Close1()" /> 
                    </div> 
                    <div class="Content" id="aaa"> 
                        <ul> 
                            <li> <a href="#" id="SysInfo"> <span>查看系统信息 </span> </a> </li> 
                            <li> <a href="#" id="SysUninstall"> <span>添加/删除程序 </span> </a> </li> 
                            <li> <a href="#" id="SysControl"> <span>更改一个设置 </span> </a> </li> 
                        </ul> 
                    </div> 
                </div> 
    </div>
     </BODY>
    </HTML>