折叠菜单实现
<!--折叠菜单，摘自网络--><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>三级折叠菜单</title><style>*,body,ul,h1,h2{ margin:0; padding:0; list-style:none;}body{font:12px "宋体"; padding-top:20px;}a{ color:#777;border:none;}#menu { width:200px; margin:auto;} #menu h1 { font-size:12px; border:#C60 1px solid; margin-top:1px; background-color:#F93;} #menu h2 { font-size:12px; border:#E7E7E7 1px solid; border-top-color:#FFF; background-color:#F4F4F4;} #menu ul { padding-left:15px; height:100px;border:#E7E7E7 1px solid; border-top:none;overflow:auto;} #menu a { display:block; padding:5px 0 3px 10px; text-decoration:none; overflow:hidden;} #menu a:hover{ color:#6F0; background:#000;} #menu .no {display:none;} #menu .h1 a{color:#6F0;} #menu .h2 a{color:#06F;} #menu h1 a{color:#FFF;}</style><script language="JavaScript"><!--//function ShowMenu(obj,n){ var Nav = obj.parentNode; if(!Nav.id){ var BName = Nav.getElementsByTagName("ul"); var HName = Nav.getElementsByTagName("h2"); var t = 2; }else{ var BName = document.getElementById(Nav.id).getElementsByTagName("span"); var HName = document.getElementById(Nav.id).getElementsByTagName("h1"); var t = 1; } for(var i=0; i<HName.length;i++){ HName[i].innerHTML = HName[i].innerHTML.replace("-","+"); HName[i].className = ""; } obj.className = "h" + t; for(var i=0; i<BName.length; i++){if(i!=n){BName[i].className = "no";}} if(BName[n].className == "no"){ BName[n].className = ""; obj.innerHTML = obj.innerHTML.replace("+","-"); }else{ BName[n].className = "no"; obj.className = ""; obj.innerHTML = obj.innerHTML.replace("-","+"); }}//--></script></head><body><div id="menu"> <h1 onClick="javascript:ShowMenu(this,0)"><a href="javascript:void(0)">+ 一级菜单A</a></a></h1> <span class="no"> <h2 onClick="javascript:ShowMenu(this,0)"><a href="javascript:void(0)">+ 一级菜单A_1</a></a></h2> <ul class="no"> <a href="javascript:void(0)">一级菜单A_0</a> <a href="javascript:void(0)">一级菜单A_1</a> <a href="javascript:void(0)">一级菜单A_2</a> <a href="javascript:void(0)">一级菜单A_3</a> <a href="javascript:void(0)">一级菜单A_4</a> <a href="javascript:void(0)">一级菜单A_5</a> <a href="javascript:void(0)">一级菜单A_6</a> <a href="javascript:void(0)">一级菜单A_7</a> <a href="javascript:void(0)">一级菜单A_8</a> <a href="javascript:void(0)">一级菜单A_9</a> </ul> <h2 onClick="javascript:ShowMenu(this,1)"><a href="javascript:void(0)">+ 一级菜单A_2</a></h2> <ul class="no"> <a href="javascript:void(0)">一级菜单A_0</a> <a href="javascript:void(0)">一级菜单A_1</a> <a href="javascript:void(0)">一级菜单A_2</a> <a href="javascript:void(0)">一级菜单A_3</a> <a href="javascript:void(0)">一级菜单A_4</a> <a href="javascript:void(0)">一级菜单A_5</a> <a href="javascript:void(0)">一级菜单A_6</a> <a href="javascript:void(0)">一级菜单A_7</a> <a href="javascript:void(0)">一级菜单A_8</a> <a href="javascript:void(0)">一级菜单A_9</a> </ul> <h2 onClick="javascript:ShowMenu(this,2)"><a href="javascript:void(0)">+ 一级菜单A_3</a></h2> <ul class="no"> <a href="javascript:void(0)">一级菜单A_0</a> <a href="javascript:void(0)">一级菜单A_1</a> <a href="javascript:void(0)">一级菜单A_2</a> <a href="javascript:void(0)">一级菜单A_3</a> <a href="javascript:void(0)">一级菜单A_4</a> <a href="javascript:void(0)">一级菜单A_5</a> <a href="javascript:void(0)">一级菜单A_6</a> <a href="javascript:void(0)">一级菜单A_7</a> <a href="javascript:void(0)">一级菜单A_8</a> <a href="javascript:void(0)">一级菜单A_9</a> </ul> <h2 onClick="javascript:ShowMenu(this,3)"><a href="javascript:void(0)">+ 一级菜单A_4</a></h2> <ul class="no"> <a href="javascript:void(0)">一级菜单A_0</a> <a href="javascript:void(0)">一级菜单A_1</a> <a href="javascript:void(0)">一级菜单A_2</a> <a href="javascript:void(0)">一级菜单A_3</a> <a href="javascript:void(0)">一级菜单A_4</a> <a href="javascript:void(0)">一级菜单A_5</a> <a href="javascript:void(0)">一级菜单A_6</a> <a href="javascript:void(0)">一级菜单A_7</a> <a href="javascript:void(0)">一级菜单A_8</a> <a href="javascript:void(0)">一级菜单A_9</a> </ul> <h2 onClick="javascript:ShowMenu(this,4)"><a href="javascript:void(0)">+ 一级菜单A_5</a></h2> <ul class="no"> <a href="javascript:void(0)">一级菜单A_0</a> <a href="javascript:void(0)">一级菜单A_1</a> <a href="javascript:void(0)">一级菜单A_2</a> <a href="javascript:void(0)">一级菜单A_3</a> <a href="javascript:void(0)">一级菜单A_4</a> <a href="javascript:void(0)">一级菜单A_5</a> <a href="javascript:void(0)">一级菜单A_6</a> <a href="javascript:void(0)">一级菜单A_7</a> <a href="javascript:void(0)">一级菜单A_8</a> <a href="javascript:void(0)">一级菜单A_9</a> </ul> <h2 onClick="javascript:ShowMenu(this,5)"><a href="javascript:void(0)">+ 一级菜单A_6</a></h2> <ul class="no"> <a href="javascript:void(0)">一级菜单A_0</a> <a href="javascript:void(0)">一级菜单A_1</a> <a href="javascript:void(0)">一级菜单A_2</a> <a href="javascript:void(0)">一级菜单A_3</a> <a href="javascript:void(0)">一级菜单A_4</a> <a href="javascript:void(0)">一级菜单A_5</a> <a href="javascript:void(0)">一级菜单A_6</a> <a href="javascript:void(0)">一级菜单A_7</a> <a href="javascript:void(0)">一级菜单A_8</a> <a href="javascript:void(0)">一级菜单A_9</a> </ul> <h2 onClick="javascript:ShowMenu(this,6)"><a href="javascript:void(0)">+ 一级菜单A_7</a></h2> <ul class="no"> <a href="javascript:void(0)">一级菜单A_0</a> <a href="javascript:void(0)">一级菜单A_1</a> <a href="javascript:void(0)">一级菜单A_2</a> <a href="javascript:void(0)">一级菜单A_3</a> <a href="javascript:void(0)">一级菜单A_4</a> <a href="javascript:void(0)">一级菜单A_5</a> <a href="javascript:void(0)">一级菜单A_6</a> <a href="javascript:void(0)">一级菜单A_7</a> <a href="javascript:void(0)">一级菜单A_8</a> <a href="javascript:void(0)">一级菜单A_9</a> </ul> <h2 onClick="javascript:ShowMenu(this,7)"><a href="javascript:void(0)">+ 一级菜单A_8</a></h2> <ul class="no"> <a href="javascript:void(0)">一级菜单A_0</a> <a href="javascript:void(0)">一级菜单A_1</a> <a href="javascript:void(0)">一级菜单A_2</a> <a href="javascript:void(0)">一级菜单A_3</a> <a href="javascript:void(0)">一级菜单A_4</a> <a href="javascript:void(0)">一级菜单A_5</a> <a href="javascript:void(0)">一级菜单A_6</a> <a href="javascript:void(0)">一级菜单A_7</a> <a href="javascript:void(0)">一级菜单A_8</a> <a href="javascript:void(0)">一级菜单A_9</a> </ul> <h2 onClick="javascript:ShowMenu(this,8)"><a href="javascript:void(0)">+ 一级菜单A_9</a></h2> <ul class="no"> <a href="javascript:void(0)">一级菜单A_0</a> <a href="javascript:void(0)">一级菜单A_1</a> <a href="javascript:void(0)">一级菜单A_2</a> <a href="javascript:void(0)">一级菜单A_3</a> <a href="javascript:void(0)">一级菜单A_4</a> <a href="javascript:void(0)">一级菜单A_5</a> <a href="javascript:void(0)">一级菜单A_6</a> <a href="javascript:void(0)">一级菜单A_7</a> <a href="javascript:void(0)">一级菜单A_8</a> <a href="javascript:void(0)">一级菜单A_9</a> </ul> <h2 onClick="javascript:ShowMenu(this,9)"><a href="javascript:void(0)">+ 一级菜单A_10</a></h2> <ul class="no"> <a href="javascript:void(0)">一级菜单A_0</a> <a href="javascript:void(0)">一级菜单A_1</a> <a href="javascript:void(0)">一级菜单A_2</a> <a href="javascript:void(0)">一级菜单A_3</a> <a href="javascript:void(0)">一级菜单A_4</a> <a href="javascript:void(0)">一级菜单A_5</a> <a href="javascript:void(0)">一级菜单A_6</a> <a href="javascript:void(0)">一级菜单A_7</a> <a href="javascript:void(0)">一级菜单A_8</a> <a href="javascript:void(0)">一级菜单A_9</a> </ul> <h2 onClick="javascript:ShowMenu(this,10)"><a href="javascript:void(0)">+ 一级菜单A_11</a></h2> <ul class="no"> <a href="javascript:void(0)">一级菜单A_0</a> <a href="javascript:void(0)">一级菜单A_1</a> <a href="javascript:void(0)">一级菜单A_2</a> <a href="javascript:void(0)">一级菜单A_3</a> <a href="javascript:void(0)">一级菜单A_4</a> <a href="javascript:void(0)">一级菜单A_5</a> <a href="javascript:void(0)">一级菜单A_6</a> <a href="javascript:void(0)">一级菜单A_7</a> <a href="javascript:void(0)">一级菜单A_8</a> <a href="javascript:void(0)">一级菜单A_9</a> </ul> <h2 onClick="javascript:ShowMenu(this,11)"><a href="javascript:void(0)">+ 一级菜单A_12</a></h2> <ul class="no"> <a href="javascript:void(0)">一级菜单A_0</a> <a href="javascript:void(0)">一级菜单A_1</a> <a href="javascript:void(0)">一级菜单A_2</a> <a href="javascript:void(0)">一级菜单A_3</a> <a href="javascript:void(0)">一级菜单A_4</a> <a href="javascript:void(0)">一级菜单A_5</a> <a href="javascript:void(0)">一级菜单A_6</a> <a href="javascript:void(0)">一级菜单A_7</a> <a href="javascript:void(0)">一级菜单A_8</a> <a href="javascript:void(0)">一级菜单A_9</a> </ul> </span> <h1 onClick="javascript:ShowMenu(this,1)"><a href="javascript:void(0)">+ 二级菜单B</a></h1> <span class="no"> <h2 onClick="javascript:ShowMenu(this,0)"><a href="javascript:void(0)">+ 二级菜单B_1</a></h2> <ul class="no"> <a href="javascript:void(0)">二级菜单B_0</a> <a href="javascript:void(0)">二级菜单B_1</a> <a href="javascript:void(0)">二级菜单B_2</a> <a href="javascript:void(0)">二级菜单B_3</a> <a href="javascript:void(0)">二级菜单B_4</a> <a href="javascript:void(0)">二级菜单B_5</a> <a href="javascript:void(0)">二级菜单B_6</a> <a href="javascript:void(0)">二级菜单B_7</a> <a href="javascript:void(0)">二级菜单B_8</a> <a href="javascript:void(0)">二级菜单B_9</a> </ul> <h2 onClick="javascript:ShowMenu(this,1)"><a href="javascript:void(0)">+ 二级菜单B_2</a></h2> <ul class="no"> <a href="javascript:void(0)">二级菜单B_0</a> <a href="javascript:void(0)">二级菜单B_1</a> <a href="javascript:void(0)">二级菜单B_2</a> <a href="javascript:void(0)">二级菜单B_3</a> <a href="javascript:void(0)">二级菜单B_4</a> <a href="javascript:void(0)">二级菜单B_5</a> <a href="javascript:void(0)">二级菜单B_6</a> <a href="javascript:void(0)">二级菜单B_7</a> <a href="javascript:void(0)">二级菜单B_8</a> <a href="javascript:void(0)">二级菜单B_9</a> </ul> </span> <h1 onClick="javascript:ShowMenu(this,2)"><a href="javascript:void(0)">+ 三级菜单C</a></h1> <span class="no"> <h2 onClick="javascript:ShowMenu(this,0)"><a href="javascript:void(0)">+ 三级菜单C_1</a></h2> <ul class="no"> <a href="javascript:void(0)">三级菜单C_0</a> <a href="javascript:void(0)">三级菜单C_1</a> <a href="javascript:void(0)">三级菜单C_2</a> <a href="javascript:void(0)">三级菜单C_3</a> <a href="javascript:void(0)">三级菜单C_4</a> <a href="javascript:void(0)">三级菜单C_5</a> <a href="javascript:void(0)">三级菜单C_6</a> <a href="javascript:void(0)">三级菜单C_7</a> <a href="javascript:void(0)">三级菜单C_8</a> <a href="javascript:void(0)">三级菜单C_9</a> </ul> <h2 onClick="javascript:ShowMenu(this,1)"><a href="javascript:void(0)">+ 三级菜单C_2</a></h2> <ul class="no"> <a href="javascript:void(0)">三级菜单C_0</a> <a href="javascript:void(0)">三级菜单C_1</a> <a href="javascript:void(0)">三级菜单C_2</a> <a href="javascript:void(0)">三级菜单C_3</a> <a href="javascript:void(0)">三级菜单C_4</a> <a href="javascript:void(0)">三级菜单C_5</a> <a href="javascript:void(0)">三级菜单C_6</a> <a href="javascript:void(0)">三级菜单C_7</a> <a href="javascript:void(0)">三级菜单C_8</a> <a href="javascript:void(0)">三级菜单C_9</a> </ul> </span> <h1 onClick="javascript:ShowMenu(this,3)"><a href="javascript:void(0)">+ 四级菜单D</a></h1> <span class="no"> <h2 onClick="javascript:ShowMenu(this,0)"><a href="javascript:void(0)">+ 四级菜单D_1</a></h2> <ul class="no"> <a href="javascript:void(0)">四级菜单D_0</a> <a href="javascript:void(0)">四级菜单D_1</a> <a href="javascript:void(0)">四级菜单D_2</a> <a href="javascript:void(0)">四级菜单D_3</a> <a href="javascript:void(0)">四级菜单D_4</a> <a href="javascript:void(0)">四级菜单D_5</a> <a href="javascript:void(0)">四级菜单D_6</a> <a href="javascript:void(0)">四级菜单D_7</a> <a href="javascript:void(0)">四级菜单D_8</a> <a href="javascript:void(0)">四级菜单D_9</a> </ul> <h2 onClick="javascript:ShowMenu(this,1)"><a href="javascript:void(0)">+ 四级菜单D_2</a></h2> <ul class="no"> <a href="javascript:void(0)">四级菜单D_0</a> <a href="javascript:void(0)">四级菜单D_1</a> <a href="javascript:void(0)">四级菜单D_2</a> <a href="javascript:void(0)">四级菜单D_3</a> <a href="javascript:void(0)">四级菜单D_4</a> <a href="javascript:void(0)">四级菜单D_5</a> <a href="javascript:void(0)">四级菜单D_6</a> <a href="javascript:void(0)">四级菜单D_7</a> <a href="javascript:void(0)">四级菜单D_8</a> <a href="javascript:void(0)">四级菜单D_9</a> </ul> </span></div></body></html>?