function Troll(id) {
	this.foldersAsLinks = false;
	this.path = "img/";
	this.img = {
		"branch": "./img/tree-branch.gif",
		"doc": "./img/tree-doc.gif",
		"folder": "./img/tree-folder.gif",
		"folderOpen": "./img/tree-folder-open.gif",
		"leaf": "./img/tree-leaf.gif",
		"leafEnd": "./img/tree-leaf-end.gif",
		"node": "./img/tree-node.gif",
		"nodeEnd": "./img/tree-node-end.gif",
		"nodeOpen": "./img/tree-node-open.gif",
		"nodeOpenEnd": "./img/tree-node-open-end.gif" };
	this.cookiePath = "";
	this.cookieDomain = "";
	this.init = function() {
		var p, img;
		for (p in this.img) {
			this.img[p] = this.path + this.img[p];
		}
		for (p in this.img) {
			this.imgObjects.push(new Image());
			this.imgObjects.getLast().src = this.img[p];
			this.img[p] = this.imgObjects.getLast().src;
		}
		this.parse(document.getElementById(this.id).childNodes, this.tree);
		this.loadState();
		if (window.addEventListener) { window.addEventListener("unload", function(e) { self.saveState(); }, false); }
		else if (window.attachEvent) { window.attachEvent("onunload", function(e) { self.saveState(); }); }
		this.updateHtml();
	};

	this.parse = function(nodes, tree) {
		for (var i = 0; i < nodes.length; i++) {
			if (nodes[i].nodeType == 1) {
				if (!nodes[i].className) { continue; }
				if (!nodes[i].id) { nodes[i].id = this.id + "-" + (++this.count); }
				var node = new Node();
				node.id = nodes[i].id;
				if (nodes[i].firstChild) {
					if (nodes[i].firstChild.tagName == "A") {
						var a = nodes[i].firstChild;
						if (a.firstChild)	{ node.text = a.firstChild.nodeValue.trim(); }
						if (a.href)		{ node.href = a.href; }
						if (a.title)		{ node.title = a.title;  }
						if (a.target)		{ node.target = a.target; }
					} else { node.text = nodes[i].firstChild.nodeValue.trim(); }
				}
				node.parentNode = tree;
				node.childNodes = (nodes[i].className == "folder" ? new Array() : null);
				node.isDoc	  = (nodes[i].className == "doc");
				node.isFolder   = (nodes[i].className == "folder");
				//if (node.childNodes == "folder") {
					tree.childNodes.push(node);
				//}
				this.allNodes[node.id] = node;
//alert (nodes[i].nodeType);
			}
			if (nodes[i].nodeType == 1 && nodes[i].childNodes) {
				//alert(i+'-'+nodes[i].childNodes);
				this.parse(nodes[i].childNodes, tree.childNodes.getLast());
			}
		}
	};

	this.nodeClick = function(id) {
		var el = document.getElementById(id+"-section");
		var node = document.getElementById(id+"-node");
		var icon = document.getElementById(id+"-icon");
		if (el.style.display == "block") {
			el.style.display = "none";
			if (this.allNodes[id].isLast()) { node.src = this.img.nodeEnd; }
			else { node.src = this.img.node; }
			icon.src = this.img.folder;
			this.opened.removeByValue(id);
		} else {
			el.style.display = "block";
			if (this.allNodes[id].isLast()) { node.src = this.img.nodeOpenEnd; }
			else { node.src = this.img.nodeOpen; }
			icon.src = this.img.folderOpen;
			this.opened.push(id);
		}
		/* fix ie bug - images not showing */
		if (node.outerHTML) { node.outerHTML = node.outerHTML; }
		if (icon.outerHTML) { icon.outerHTML = icon.outerHTML; }
	};
	this.toHtml = function() {
		var s = "";
		var nodes = this.tree.childNodes;
		for (var i = 0; i < nodes.length; i++) {
			s += nodes[i].toHtml();
		}
		return s;
	};
	this.updateHtml = function() {
		document.getElementById(this.id).innerHTML = this.toHtml();
	};
	this.loadState = function() {
		var opened = this.cookie.get("opened");
		if (opened) {
			this.opened = opened.split("|");
			this.opened.filter(function(id) { return self.allNodes[id] && self.allNodes[id].isFolder && self.allNodes[id].childNodes.length;  });
		}
	};
	this.saveState = function() {
		if (this.opened.length) {
			this.cookie.set("opened", this.opened.join("|"), 3600*24*30, this.cookiePath, this.cookieDomain);
		} else {
			this.clearState();
		}
	};
	this.clearState = function() {
		this.cookie.del("opened");
	};
	function Node(id, text, parentNode, childNodes, isDoc, isFolder) {
		this.id = id;
		this.text = text;
		this.parentNode = parentNode;
		this.childNodes = childNodes;
		this.isDoc = isDoc;
		this.isFolder = isFolder;
		this.href = "";
		this.title = "";
		this.target = "";
		this.isLast = function() {
			if (this.parentNode) {
				return this.parentNode.childNodes.getLast().id == this.id;
			}
			throw "Troll.Node.isLast() failed, this func cannot be called for the root element";
		};

		this.toHtml = function() {
			var s = '<div class="?" id="?">'.format((this.isFolder ? "folder" : "doc"), this.id);
			if(this.href==location.href){ _tag='<a href="?"??><b>?</b></a>' } else { _tag='<a href="?"??>?</a>' }


			if (this.isFolder) {
				var nodeIcon;
				if (this.childNodes.length) {
					nodeIcon = (self.opened.contains(this.id) ? (this.isLast() ? self.img.nodeOpenEnd : self.img.nodeOpen) : (this.isLast() ? self.img.nodeEnd : self.img.node));
				} else {
					nodeIcon = (this.isLast() ? self.img.leafEnd : self.img.leaf);
				}
				var icon = ((self.opened.contains(this.id) && this.childNodes.length) ? self.img.folderOpen : self.img.folder);
				if (this.childNodes.length) { s += '<a href="javascript:void(0)" onclick="?.nodeClick(\'?\')">'.format(self.id, this.id); }
				s += '<img id="?-node" src="?" width="18" height="18" alt="" />'.format(this.id, nodeIcon);
				if (this.childNodes.length) { s += '</a>'; }
				s += '<img id="?-icon" src="?" width="18" height="18" alt="" />'.format(this.id, icon);
				if (self.foldersAsLinks) {
					s += _tag.format(this.href, (this.title ? ' title="?"'.format(this.title) : ""), (this.target ? ' target="?"'.format(this.target) : ""), this.text);
				} else {
					s += this.text;
				}
				if (this.childNodes.length) {
					s += '<div class="section?" id="?-section"'.format((this.isLast() ? " last" : ""), this.id);
					if (self.opened.contains(this.id)) {
						s += '  style="display: block;"'; }
					s += '>';
					for (var i = 0; i < this.childNodes.length; i++) {
						s += this.childNodes[i].toHtml();
					}
					s += '</div>';
				}
			}
			if (this.isDoc) {
				s += '<img src="?" width="18" height="18" alt="" /><img src="?" width="18" height="18" alt="" />'.format((this.isLast() ? self.img.leafEnd : self.img.leaf), self.img.doc);
				s += _tag.format(this.href, (this.title ? ' title="?"'.format(this.title) : ""), (this.target ? ' target="?"'.format(this.target) : ""), this.text);
			}
			s += '</div>';
			return s;
		};
	}
	function Cookie() {
		this.get = function(name) {
			var cookies = document.cookie.split(";");
			for (var i = 0; i < cookies.length; ++i) {
				var a = cookies[i].split("=");
				if (a.length == 2) {
					a[0] = a[0].trim();
					a[1] = a[1].trim();
					if (a[0] == name) {
						return unescape(a[1]);
					}
				}
			}
			return "";
		};
		this.set = function(name, value, seconds, path, domain, secure) {
			var cookie = (name + "=" + escape(value));
			if (seconds) {
				var date = new Date(new Date().getTime()+seconds*1000);
				cookie += ("; expires="+date.toGMTString());
			}
			cookie += (path	? "; path="+path : "");
			cookie += (domain  ? "; domain="+domain : "");
			cookie += (secure  ? "; secure" : "");
			document.cookie = cookie;
		};
		this.del = function(name) {
			document.cookie = name + "=; expires=Thu, 01-Jan-70 00:00:01 GMT";
		};
	}
	var self = this;
	this.id = id;
	this.tree = new Node("tree", "", null, new Array(), false, true);
	this.allNodes = {}; // id => object
	this.opened = []; // opened folders
	this.active = ""; // active node, text clicked
	this.cookie = new Cookie();
	this.imgObjects = [];
	this.count = 0;
}

/* Check whether array contains given string */
if (!Array.prototype.contains) {
	Array.prototype.contains = function(s) {
		for (var i = 0; i < this.length; ++i) { if (this[i] === s) { return true; } }
		return false;
	};
}

/* Remove elements with such value (mutates) */
if (!Array.prototype.removeByValue) {
	Array.prototype.removeByValue = function(value) {
		var i, indexes = [];
		for (i = 0; i < this.length; ++i) { if (this[i] === value) { indexes.push(i); } }
		for (i = indexes.length - 1; i >= 0; --i) { this.splice(indexes[i], 1); }
	};
}

/* Remove elements judged 'false' by the passed function (mutates) */
if (!Array.prototype.filter) {
	Array.prototype.filter = function(func) {
		var i, indexes = [];
		for (i = 0; i < this.length; ++i) { if (!func(this[i])) { indexes.push(i); } }
		for (i = indexes.length - 1; i >= 0; --i) { this.splice(indexes[i], 1); }
	};
}

/* Get the last element from the array */
if (!Array.prototype.getLast) {
	Array.prototype.getLast = function() { return this[this.length-1]; };
}

/* Strip whitespace from the beginning and end of a string */
if (!String.prototype.trim) {
	String.prototype.trim = function() { return this.replace(/^\s*|\s*$/g, ""); };
}

/* Replace ? tokens with variables passed as arguments in a string */
String.prototype.format = function() {
	if (!arguments.length) { throw "String.format() failed, no arguments passed, this = "+this; }
	var tokens = this.split("?");
	if (arguments.length != (tokens.length - 1)) { throw "String.format() failed, tokens != arguments, this = "+this; }
	var s = tokens[0];
	for (var i = 0; i < arguments.length; ++i) { s += (arguments[i] + tokens[i + 1]); }
	return s;
};