JavaScript - Problem With Collapsing/expanding Menu - Accordion

function initMenus() {
	$('ul.menu ul').hide();
	$.each($('ul.menu'), function(){
		$('#' + this.id + '.expandfirst ul:first).show();
	});
	$('ul.menu li a').click(
		function() {
			var checkElement = $(this).next();
			var parent = this.parentNode.parentNode.id;

			if($('#' + parent).hasClass('noaccordion')) {
				$(this).next().slideToggle('normal');
				return false;
			}
			if((checkElement.is('ul')) && (checkElement.is(':visible'))) {
				if($('#' + parent).hasClass('collapsible')) {
					$('#' + parent + ' ul:visible').slideUp('normal');
				}
				return false;
			}
			if((checkElement.is('ul')) && (!checkElement.is(':visible'))) {
				$('#' + parent + ' ul:visible').slideUp('normal');
				checkElement.slideDown('normal');
				return false;
			}
		}
	);
}
$(document).ready(function() {initMenus();});

<ul>
<li><a href="1.php">Things</a></li>
<li><a href="2.php">Animals</a>
  <ul>
    <li><a href="2-1.php">Cani</a>
        <ul>
          <li><a href="2-1-1.php">Domestic dogs</a></li>
          <li><a href="2-1-2.php">Wolves</a></li>
        </ul>
    </li>
    <li><a href="2-2.php">Felidae</a>
        <ul>
          <li><a href="2-2-1.php">Domestic cats</a></li>
          <li><a href="2-2-2.php">Wild cats</a></li>
        </ul>
    </li>
  </ul>
</li>
<li><a href="3.php">Humans</a></li>
</ul>

div#s1 {
width: 200px;          /* menu width */
}

div#s1 ul {
background-color: #036;
list-style-type: none; /* get rid of the bullets */
padding:0;             /* no padding */
margin:0;              /* no margin for IE either */
}

div#s1 ul li {
margin: 0;
padding: 0;
background-color: #036;
display:block;
border-top: 1px solid white; /* lines */
}

div#s1 ul li a {
display: block;         /* lines extend to right, make area clickable */
color: white;
background-color: #036;
padding: 3px 3px 3px 23px;
margin:0;
text-decoration: none;
height:15px;           /* hint for IE, alternatively remove whitespace from HTML */
}

div#s1 ul ul li a {
margin-left: 20px;     /* indent level 1 */
}

div#s1 ul ul ul li a {
margin-left: 40px;     /* indent level 2 */
}

div#s1 ul ul ul ul li a {
margin-left: 60px;     /* indent level 3 */
}

div#s1 li ul, div#s1 li.open li.closed ul {
display: none;         /* collapse */
}

div#s1 li.open ul {
display: block;        /* expand */
}

div#s1 ul li.open a {
background-image: url(bullet_open.gif);
background-repeat: no-repeat;
}

div#s1 ul li.closed a {
background-image: url(bullet_closed.gif);
background-repeat: no-repeat;
}

div#s1 ul li.leaf a {
background-image: url(bullet_leaf.gif);
background-repeat: no-repeat;
}

div#s1 li.active a {
background-position: 0px -20px;
color: red;            /* highlight text */
}

div#s1 li.active li a {
background-position: 0px 0px;
color: white;          /* fix lower levels */
}

div#s1 ul li a:hover {
color: red;
background-color: #06C; /* rollover effect */
}

var menu_active_class = "active";
var menu_leaf_class = "leaf";
var menu_open_class = "open";
var menu_closed_class = "closed";

//the default page that is displayed if URL ends in /
var menu_default_page = "index.php";
var menu_url;

//main function
//menu_id : id of the element containing the navigation
function menu_main(menu_id) {
 var url = location.href;
 if (url.lastIndexOf("/") == (url.length-1)) {
   url = url+menu_default_page;
 }
 if (url.lastIndexOf("?") >= 0) {
   url = url.substring(0, url.lastIndexOf("?"));
 }
 if (url.lastIndexOf("#") >= 0) {
   url = url.substring(0, url.lastIndexOf("#"));
 }
 menu_url = url;

 var main = document.getElementById(menu_id);
 if (!main) alert("No element with id '"+ menu_id +"' found");
 menu_traverse(main);
 }

 /* Walks down the subtree and on the way back
 sets properties.
 returns bit set
         1: set = element is a node, unset = element is a leaf
         2: set = element contains the active node
         4: set = element is the active A node
*/
function menu_traverse(element) {
var props  = 0;

// walk down
for (var i=0; i<element.childNodes.length; i++) {
  var child = element.childNodes[i];
  props |= menu_traverse(child); // aggregate bits
}

// on the way back now
switch (element.tagName) {
  case "UL":
    props |= 1;
    break;

  case "LI":
    var c1 = (props & 1) ? 
               ((props & (2|4)) ? menu_open_class : menu_closed_class)
             : menu_leaf_class; 
    element.className = element.className ? element.className+" "+c1 : c1;
    if (props & 4) {
      if (!(props & 2)) element.className += " "+menu_active_class;
      props |= 2;
      props &= 1 | 2; // reset bit 4
    }
    break;

  case "A":
    if (props & 2) break; // once is enough
    var href = element.getAttribute("href");
    if (menu_isSameUrl(menu_url, href)) props |= 4;
    break;
  }

  return props;
}

//matches two URIs when href is the last part of url
//.. and . are correctly resolved
function menu_isSameUrl(url, href) {
var a = url.split(/[?\/]/i);
var b = href.split(/[?\/]/i);
var i = a.length - 1;
var j = b.length - 1;
while ((i >= 0) && (j >= 0)) {
  if (b[j] == "..") { j-=2; continue; }
  if (a[i] == "..") { i-=2; continue; }
  if ((b[j] == ".") || (b[j] == "")) { j--; continue; }
  if ((a[i] == ".") || (a[i] == "")) { i--; continue; }
  if (! (a[i] == b[j])) return false;
  i--;
  j--;
 }
 return true;
}

function initMenu(){
  var menus, menu, text, a, i, CurrentID;
  menus = getChildrenByElement(document.getElementById("menu"));
  CurrentID = document.getElementById("auto");
  for(i = 0; i < menus.length; i++){
    menu = menus[i];
    text = getFirstChildByText(menu);
    a = document.createElement("a");
    menu.replaceChild(a, text);
    a.appendChild(text);
    a.href = "#";
    a.onclick = showMenu;
    a.onfocus = function(){this.blur()};
	
  }

  //CurrentID.showMenu; thought this would work but it doesn.t
}

<!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>Untitled Document</title>
<script>

function accordion(openAccordionID){
	
	document.getElementById("content"+openAccordionID).style.display = 
	(document.getElementById("content"+openAccordionID).style.display == "none") 
	? "block" : "none" ;
	
	var sumAccordion;
	if(document.all){
		sumAccordion = document.body.getElementsByTagName("div").length/2;		
		}
	else {sumAccordion = document.getElementsByClassName("content").length;}
	
	for(var closeAccordionID=1; closeAccordionID<=sumAccordion; closeAccordionID++){
		if(closeAccordionID == openAccordionID){continue;}
		document.getElementById("content"+closeAccordionID).style.display = "none";

		}

	addHeight(openAccordionID);
	cutHeight(closeAccordionID);
	
	}

	var h=0;
	var t;
	function addHeight(openAccordionID){
		clearInterval(t);
		document.getElementById("content"+openAccordionID).style.height = h+"px";
		h+=1;
		t = setInterval("addHeight('"+openAccordionID+"')",10);
		if(h==100){clearInterval(t);h=0;}
			}
	
	var T;
	function cutHeight(closeAccordionID){
		var h=100;
		clearInterval(T);
		document.getElementById("content"+closeAccordionID).style.height = h+"px";
		h-=1;
		T = setInterval("cutHeight('"+closeAccordionID+"')",10);
		if(h==0){clearInterval(T);}
			}

</script>
<style>
.menu {
	background-color: #6F6;
	width: 200px;
	height: 50px;}
.content {
	display: none;
	background-color: yellow;
	width: 200px;
	height:0px;
	overflow: hidden;}

</style>
</head>
<body>
<div onclick="accordion(1)" class="menu">Menu 1</div>
<div id="content1" class="content">Content 1</div>
<div onclick="accordion(2)" class="menu">Menu 2</div>
<div id="content2" class="content">Content 2</div>
<div onclick="accordion(3)" class="menu">Menu 3</div>
<div id="content3" class="content">Content 3</div>
</body>
</html>

var menu=function(){
	var t=15,z=50,s=6,a;
	function dd(n){this.n=n; this.h=[]; this.c=[]}
	dd.prototype.init=function(p,c){
		a=c; var w=document.getElementById(p), s=w.getElementsByTagName('ul'), l=s.length, i=0;
		for(i;i<l;i++){
			var h=s[i].parentNode; this.h[i]=h; this.c[i]=s[i];
			h.onmouseover=new Function(this.n+'.st('+i+',true)');
			h.onmouseout=new Function(this.n+'.st('+i+')');
		}
	}
	dd.prototype.st=function(x,f){
		var c=this.c[x], h=this.h[x], p=h.getElementsByTagName('a')[0];
		clearInterval(c.t); c.style.overflow='hidden';
		if(f){
			p.className+=' '+a;
			if(!c.mh){c.style.display='block'; c.style.height=''; c.mh=c.offsetHeight; c.style.height=0}
			if(c.mh==c.offsetHeight){c.style.overflow='visible'}
			else{c.style.zIndex=z; z++; c.t=setInterval(function(){sl(c,1)},t)}
		}else{p.className=p.className.replace(a,''); c.t=setInterval(function(){sl(c,-1)},t)}
	}
	function sl(c,f){
		var h=c.offsetHeight;
		if((h<=0&&f!=1)||(h>=c.mh&&f==1)){
			if(f==1){c.style.filter=''; c.style.opacity=1; c.style.overflow='visible'}
			clearInterval(c.t); return
		}
		var d=(f==1)?Math.ceil((c.mh-h)/s):Math.ceil(h/s), o=h/c.mh;
		c.style.opacity=o; c.style.filter='alpha(opacity='+(o*100)+')';
		c.style.height=h+(d*f)+'px'
	}
	return{dd:dd}
}();

var menu=new menu.dd("menu");
menu.init("menu","menuhover");