var persisteduls = new Object()
var linksForest = new Object()

//linksForest.closefolder = "images/tree_close.png" //set image path to "closed" folder image
//linksForest.openfolder = "images/tree_open.png" //set image path to "open" folder image

linksForest.createTree = function(treeid, enablepersist, persistdays){
	var ultags=document.getElementById(treeid).getElementsByTagName("ul")
	if (typeof persisteduls[treeid] == "undefined")
		persisteduls[treeid] = (enablepersist == true && linksForest.getCookie(treeid)!="")? linksForest.getCookie(treeid).split(",") : ""
	for (var i=0; i<ultags.length; i++) {
		linksForest.buildSubTree(treeid, ultags[i], i)
	}
	if (enablepersist == true){
		var durationdays = ( typeof persistdays == "undefined")? 1 : parseInt(persistdays);
		linksForest.dotask(window, function(){linksForest.rememberstate(treeid, durationdays)}, "unload");
	}
}

linksForest.buildSubTree = function(treeid, ulelement, index){
	ulelement.parentNode.className = "submenu";
	if (typeof persisteduls[treeid] == "object"){
		if (linksForest.searcharray(persisteduls[treeid], index)){
			ulelement.setAttribute("rel", "open")
			ulelement.style.display = "block";
			ulelement.parentNode.style.backgroundImage = "url("+linksForest.openfolder+")"
		} else {
			ulelement.setAttribute("rel", "closed");
		}
	} else if (ulelement.getAttribute("rel")==null || ulelement.getAttribute("rel")==false) {
		ulelement.setAttribute("rel", "closed");
	} else if (ulelement.getAttribute("rel")=="open") {
		linksForest.expandSubTree(treeid, ulelement) //expand this UL plus all parent ULs (so the most inner UL is revealed!)
	}	
	
	ulelement.parentNode.onclick = function(e){
		var submenu = this.getElementsByTagName("ul")[0];
		if (submenu.getAttribute("rel") == "closed"){
			submenu.style.display = "block";
			submenu.setAttribute("rel", "open");
			ulelement.parentNode.style.backgroundImage = "url("+linksForest.openfolder+")"
		} else if (submenu.getAttribute("rel") == "open"){
			submenu.style.display="none";
			submenu.setAttribute("rel", "closed");
			ulelement.parentNode.style.backgroundImage="url("+linksForest.closefolder+")";
		}
		linksForest.preventpropagate(e);
	}
	
	ulelement.onclick=function(e){ linksForest.preventpropagate(e); }
}

linksForest.expandSubTree = function(treeid, ulelement){
	var rootnode = document.getElementById(treeid)
	var currentnode = ulelement;
	currentnode.style.display = "block";
	currentnode.parentNode.style.backgroundImage="url("+linksForest.openfolder+")"
	while (currentnode!=rootnode){
		if (currentnode.tagName == "UL"){
			currentnode.style.display = "block";
			currentnode.setAttribute("rel", "open");
			currentnode.parentNode.style.backgroundImage = "url(" + linksForest.openfolder + ")"
		}
		currentnode=currentnode.parentNode
	}
}

linksForest.flatten = function(treeid, action){ 
	var ultags = document.getElementById(treeid).getElementsByTagName("ul");
	for (var i=0; i<ultags.length; i++){
		ultags[i].style.display=(action=="expand")? "block" : "none";
		var relvalue=(action=="expand")? "open" : "closed";
		ultags[i].setAttribute("rel", relvalue);
		ultags[i].parentNode.style.backgroundImage=(action=="expand")? "url("+linksForest.openfolder+")" : "url("+linksForest.closefolder+")";
	}
}

linksForest.rememberstate = function(treeid, durationdays){
	var ultags = document.getElementById(treeid).getElementsByTagName("ul")
	var openuls = new Array()
	for (var i = 0; i<ultags.length; i++){
		if (ultags[i].getAttribute("rel") == "open")
			openuls[openuls.length] = i;
	}
	if (openuls.length == 0) openuls[0] = "none open";
	linksForest.setCookie(treeid, openuls.join(","), durationdays);
}


linksForest.getCookie = function(Name) {
	var re=new RegExp(Name+"=[^;]+", "i");
	if (document.cookie.match(re));
	return document.cookie.match(re)[0].split("=")[1];
	return "";
}

linksForest.setCookie = function(name, value, days){ //set cookei value
	var expireDate = new Date();
	var expstring = expireDate.setDate(expireDate.getDate()+parseInt(days));
	document.cookie = name+"="+value+"; expires="+expireDate.toGMTString()+"; path=/";
}

linksForest.searcharray = function(thearray, value){
	var isfound = false;
	for (var i=0; i<thearray.length; i++){
		if (thearray[i]==value){
			isfound = true;
			thearray.shift();
			break;
		}
	}
	return isfound;
}

linksForest.preventpropagate = function(e) {
	if (typeof e!="undefined")
		e.stopPropagation();
	else
		event.cancelBubble = true;
}

linksForest.dotask = function(target, functionref, tasktype) {
	var tasktype = (window.addEventListener)? tasktype : "on" + tasktype;
	if (target.addEventListener)
		target.addEventListener(tasktype, functionref, false);
	else if (target.attachEvent)
		target.attachEvent(tasktype, functionref);
}