树型菜单,JavaScript

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title>tree menu by jiarry</title>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<script language="JavaScript" type="text/JavaScript">
<!--//made by jiarry.126.com Aug.27 2004
function showhide_obj(obj,icon)
{
obj=document.getElementById(obj);
icon=document.getElementById(icon);
//objStr=obj.toString();
//alert(objStr)
/*objStr=2;
a=objStr.toString()+5;
b=objStr+5
alert(a);alert(b);
*/

if (obj.style.display=="none")
{
 //div_list = document.all.tags("div"); //指定文档中的对象为div,仅适用于IE;
 div_list = document.getElementsByTagName("div");
 for (i=0; i< div_list.length; i ++) {
 thisDiv = div_list[i];
 if(thisDiv.id.indexOf("title")!=-1)//当文档div中的id含有list时,与charAt类似;
 {
 //if(obj.id!=obj)//该div 的id又非选中的obj,设置该div的style为none
 //{
 thisDiv.style.display="none";//循环吧所有菜单链接都隐藏起来
// }
 }
}

 //myfont=document.all.tags("font");
 myfont=document.getElementsByTagName("font");
 for(i=0;i<myfont.length;i++)
 {
 thisfont = myfont[i];
 if(thisfont.id.indexOf("icon")!=-1 && icon.id!=icon)
 {
 //alert(thisfont.id)
 //thisfont.innerHTML="+";
 }
 }
 //icon.innerHTML="-";
 obj.style.display=""; //只显示当前链接
}
else
{//假如当前对象是打开的，就关闭它;
 //icon.innerHTML="+";
 obj.style.display="none";
 }
}

function set_initialization(obj,img)
{//设置初始状态,打开一个层;
   obj.style.display="";
   img.src="images/icon/minus.gif";
   }