dTree/dtree.js/2.05

About
This is the original 2003 version from the dtree site. It doesn't seem to have any option to prepend a path to the images, so either they all have to be in an /img subfolder of the calling HTML page's folder or else you have to fully specify every icon image.

The formatting has been slightly tidied for this venue but the code is unaltered.

Code
/*--|
 * dTree 2.05 | www.destroydrop.com/javascript/tree/ |
 * Copyright (c) 2002-2003 Geir Landrö              |
 * This script can be used freely as long as all    |
 * copyright messages are intact.                   |
 * Updated: 17.04.2003                              |
 * copyright messages are intact.                   |
 * Updated: 17.04.2003                              |
 * Updated: 17.04.2003                              |

// Node object

function Node(id, pid, name, url, title, target, icon, iconOpen, open) { this.id = id; this.pid = pid; this.name = name; this.url = url; this.title = title; this.target = target; this.icon = icon; this.iconOpen = iconOpen; this._io = open || false; this._is = false; this._ls = false; this._hc = false; this._ai = 0; this._p; };

// Tree object

function dTree(objName) { this.config = { target		: null, folderLinks	: true, useSelection	: true, useCookies	: true, useLines	: true, useIcons	: true, useStatusText	: false, closeSameLevel	: false, inOrder		: false }

this.icon = { root		: 'img/base.gif', folder		: 'img/folder.gif', folderOpen	: 'img/folderopen.gif', node		: 'img/page.gif', empty		: 'img/empty.gif', line		: 'img/line.gif', join		: 'img/join.gif', joinBottom	: 'img/joinbottom.gif', plus		: 'img/plus.gif', plusBottom	: 'img/plusbottom.gif', minus		: 'img/minus.gif', minusBottom	: 'img/minusbottom.gif', nlPlus		: 'img/nolines_plus.gif', nlMinus		: 'img/nolines_minus.gif' };	this.obj = objName; this.aNodes = []; this.aIndent = []; this.root = new Node(-1); this.selectedNode = null; this.selectedFound = false; this.completed = false; };

// Adds a new node to the node array

dTree.prototype.add = function(id, pid, name, url, title, target, icon, iconOpen, open) { this.aNodes[this.aNodes.length] = new Node(id, pid, name, url, title, target, icon, iconOpen, open); };

// Open/close all nodes

dTree.prototype.openAll = function { this.oAll(true); };

dTree.prototype.closeAll = function { this.oAll(false); };

// Outputs the tree to the page

dTree.prototype.toString = function { var str = ' \n'; if (document.getElementById) { if (this.config.useCookies) this.selectedNode = this.getSelected; str += this.addNode(this.root); } else str += 'Browser not supported.'; str += ' '; if (!this.selectedFound) this.selectedNode = null; this.completed = true; return str; };

// Creates the tree structure

dTree.prototype.addNode = function(pNode) { var str = ''; var n=0; if (this.config.inOrder) n = pNode._ai; for (n; n<this.aNodes.length; n++) { if (this.aNodes[n].pid == pNode.id) { var cn = this.aNodes[n]; cn._p = pNode; cn._ai = n;			this.setCS(cn); if (!cn.target && this.config.target) cn.target = this.config.target; if (cn._hc && !cn._io && this.config.useCookies) cn._io = this.isOpen(cn.id); if (!this.config.folderLinks && cn._hc) cn.url = null; if (this.config.useSelection && cn.id == this.selectedNode && !this.selectedFound) { cn._is = true; this.selectedNode = n;					this.selectedFound = true; }			str += this.node(cn, n); if (cn._ls) break; }	}	return str; };

// Creates the node icon, url and text

dTree.prototype.node = function(node, nodeId) { var str = ' ' + this.indent(node, nodeId); if (this.config.useIcons) { if (!node.icon) node.icon = (this.root.id == node.pid) ? this.icon.root : ((node._hc) ? this.icon.folder : this.icon.node); if (!node.iconOpen) node.iconOpen = (node._hc) ? this.icon.folderOpen : this.icon.node; if (this.root.id == node.pid) { node.icon = this.icon.root; node.iconOpen = this.icon.root; }		str += ''; }	if (node.url) { str += ''; }	else if ((!this.config.folderLinks || !node.url) && node._hc && node.pid != this.root.id) str += ''; str += node.name; if (node.url || ((!this.config.folderLinks || !node.url) && node._hc)) str += ''; str += ' '; if (node._hc) { str += ''; str += this.addNode(node); str += ' '; }	this.aIndent.pop; return str; };

// Adds the empty and line icons

dTree.prototype.indent = function(node, nodeId) { var str = ''; if (this.root.id != node.pid) { for (var n=0; n'; (node._ls) ? this.aIndent.push(0) : this.aIndent.push(1); if (node._hc) { str += ''; } else str += ''; }	return str; };

// Checks if a node has any children and if it is the last sibling

dTree.prototype.setCS = function(node) { var lastId; for (var n=0; n<this.aNodes.length; n++) { if (this.aNodes[n].pid == node.id) node._hc = true; if (this.aNodes[n].pid == node.pid) lastId = this.aNodes[n].id; }	if (lastId==node.id) node._ls = true; };

// Returns the selected node

dTree.prototype.getSelected = function { var sn = this.getCookie('cs' + this.obj); return (sn) ? sn : null; };

// Highlights the selected node

dTree.prototype.s = function(id) { if (!this.config.useSelection) return; var cn = this.aNodes[id]; if (cn._hc && !this.config.folderLinks) return; if (this.selectedNode != id) { if (this.selectedNode || this.selectedNode==0) { eOld = document.getElementById("s" + this.obj + this.selectedNode); eOld.className = "node"; }		eNew = document.getElementById("s" + this.obj + id); eNew.className = "nodeSel"; this.selectedNode = id; if (this.config.useCookies) this.setCookie('cs' + this.obj, cn.id); } };

// Toggle Open or close

dTree.prototype.o = function(id) { var cn = this.aNodes[id]; this.nodeStatus(!cn._io, id, cn._ls); cn._io = !cn._io; if (this.config.closeSameLevel) this.closeLevel(cn); if (this.config.useCookies) this.updateCookie; };

// Open or close all nodes

dTree.prototype.oAll = function(status) { for (var n=0; n<this.aNodes.length; n++) { if (this.aNodes[n]._hc && this.aNodes[n].pid != this.root.id) { this.nodeStatus(status, n, this.aNodes[n]._ls) this.aNodes[n]._io = status; }	}	if (this.config.useCookies) this.updateCookie; };

// Opens the tree to a specific node

dTree.prototype.openTo = function(nId, bSelect, bFirst) { if (!bFirst) { for (var n=0; n<this.aNodes.length; n++) { if (this.aNodes[n].id == nId) { nId=n; break; }		}	}	var cn=this.aNodes[nId]; if (cn.pid==this.root.id || !cn._p) return; cn._io = true; cn._is = bSelect; if (this.completed && cn._hc) this.nodeStatus(true, cn._ai, cn._ls); if (this.completed && bSelect) this.s(cn._ai); else if (bSelect) this._sn=cn._ai; this.openTo(cn._p._ai, false, true); };

// Closes all nodes on the same level as certain node

dTree.prototype.closeLevel = function(node) { for (var n=0; n<this.aNodes.length; n++) { if (this.aNodes[n].pid == node.pid && this.aNodes[n].id != node.id && this.aNodes[n]._hc) { this.nodeStatus(false, n, this.aNodes[n]._ls); this.aNodes[n]._io = false; this.closeAllChildren(this.aNodes[n]); }	} }

// Closes all children of a node

dTree.prototype.closeAllChildren = function(node) { for (var n=0; n<this.aNodes.length; n++) { if (this.aNodes[n].pid == node.id && this.aNodes[n]._hc) { if (this.aNodes[n]._io) this.nodeStatus(false, n, this.aNodes[n]._ls); this.aNodes[n]._io = false; this.closeAllChildren(this.aNodes[n]); }	} }

// Change the status of a node(open or closed)

dTree.prototype.nodeStatus = function(status, id, bottom) { eDiv	= document.getElementById('d' + this.obj + id); eJoin	= document.getElementById('j' + this.obj + id); if (this.config.useIcons) { eIcon	= document.getElementById('i' + this.obj + id); eIcon.src = (status) ? this.aNodes[id].iconOpen : this.aNodes[id].icon; }	eJoin.src = (this.config.useLines)? ((status)?((bottom)?this.icon.minusBottom:this.icon.minus):((bottom)?this.icon.plusBottom:this.icon.plus)): ((status)?this.icon.nlMinus:this.icon.nlPlus); eDiv.style.display = (status) ? 'block': 'none'; };

// [Cookie] Clears a cookie

dTree.prototype.clearCookie = function { var now = new Date; var yesterday = new Date(now.getTime - 1000 * 60 * 60 * 24); this.setCookie('co'+this.obj, 'cookieValue', yesterday); this.setCookie('cs'+this.obj, 'cookieValue', yesterday); };

// [Cookie] Sets value in a cookie

dTree.prototype.setCookie = function(cookieName, cookieValue, expires, path, domain, secure) { document.cookie = escape(cookieName) + '=' + escape(cookieValue) + (expires ? '; expires=' + expires.toGMTString : '') + (path ? '; path=' + path : '') + (domain ? '; domain=' + domain : '') + (secure ? '; secure' : ''); };

// [Cookie] Gets a value from a cookie

dTree.prototype.getCookie = function(cookieName) { var cookieValue = ''; var posName = document.cookie.indexOf(escape(cookieName) + '='); if (posName != -1) { var posValue = posName + (escape(cookieName) + '=').length; var endPos = document.cookie.indexOf(';', posValue); if (endPos != -1) cookieValue = unescape(document.cookie.substring(posValue, endPos)); else cookieValue = unescape(document.cookie.substring(posValue)); }	return (cookieValue); };

// [Cookie] Returns ids of open nodes as a string

dTree.prototype.updateCookie = function { var str = ''; for (var n=0; n<this.aNodes.length; n++) { if (this.aNodes[n]._io && this.aNodes[n].pid != this.root.id) { if (str) str += '.'; str += this.aNodes[n].id; }	}	this.setCookie('co' + this.obj, str); };

// [Cookie] Checks if a node id is in a cookie

dTree.prototype.isOpen = function(id) { var aOpen = this.getCookie('co' + this.obj).split('.'); for (var n=0; n<aOpen.length; n++) if (aOpen[n] == id) return true; return false; };

// If Push and pop is not implemented by the browser

if (!Array.prototype.push) { Array.prototype.push = function array_push { for(var i=0;i<arguments.length;i++) this[this.length]=arguments[i]; return this.length; } };

if (!Array.prototype.pop) { Array.prototype.pop = function array_pop { lastElement = this[this.length-1]; this.length = Math.max(this.length-1,0); return lastElement; } };