var linksMenu = {
	menusmap: {},

	effects: {
		delayhide: 200, 
		shadow: { enabled:true, opacity:0.3, depth: [5, 5] }
	},

	dimensions: {},

	getoffset:function(what, offsettype) {
		return (what.offsetParent) ? what[offsettype] + this.getoffset(what.offsetParent, offsettype) : what[offsettype];
	},

	getoffsetof:function(el) {
		el._offsets = {
			left:this.getoffset(el, "offsetLeft"), 
			top:this.getoffset(el, "offsetTop"), 
			h: el.offsetHeight
		};
	},

	getdimensions:function(menu) {
		this.dimensions = { 
			anchorw:menu.anchorobj.offsetWidth, 
			anchorh:menu.anchorobj.offsetHeight,
			docwidth:(window.innerWidth ||this.standardbody.clientWidth)-20,
			docheight:(window.innerHeight ||this.standardbody.clientHeight)-15,
			docscrollx:window.pageXOffset || this.standardbody.scrollLeft,
			docscrolly:window.pageYOffset || this.standardbody.scrollTop
		};

		if (!this.dimensions.dropmenuw) {
			this.dimensions.dropmenuw = menu.dropmenu.offsetWidth;
			this.dimensions.dropmenuh = menu.dropmenu.offsetHeight;
		}
	},

	isContained:function(m, e) {
		var e = window.event || e;
		var c = e.relatedTarget || ((e.type=="mouseover") ? e.fromElement : e.toElement);

		while (c && c != m) {
			try {
				c = c.parentNode;
			}
			catch (e) {
				c = m;
			}
		}

		if (c == m)
			return true;
		else
			return false;
	},

	setopacity:function(el, value) {
		el.style.opacity = value;
		if (typeof el.style.opacity != "string") { //if it's not a string (ie: number instead), it means property not supported
			el.style.MozOpacity = value;
			if (el.filters) {
				el.style.filter = "progid:DXImageTransform.Microsoft.alpha(opacity="+ value*100 +")";
			}
		}
	},

	showmenu:function(menuid) {
		var menu = linksMenu.menusmap[menuid];

		clearTimeout(menu.hidetimer);

		this.getoffsetof(menu.anchorobj);
		this.getdimensions(menu);

		var posx = menu.anchorobj._offsets.left + (menu.orientation=="lr" ? this.dimensions.anchorw : 0); //base x pos
		var posy = menu.anchorobj._offsets.top + this.dimensions.anchorh - (menu.orientation=="lr" ? this.dimensions.anchorh : 0); //base y pos
		if (posx + this.dimensions.dropmenuw + this.effects.shadow.depth[0] > this.dimensions.docscrollx + this.dimensions.docwidth) { //drop left instead?
			posx = posx - this.dimensions.dropmenuw + (menu.orientation=="lr" ? - this.dimensions.anchorw : this.dimensions.anchorw);
		}
		if (posy + this.dimensions.dropmenuh > this.dimensions.docscrolly + this.dimensions.docheight) {  //drop up instead?
			posy = Math.max(posy - this.dimensions.dropmenuh - (menu.orientation=="lr" ? - this.dimensions.anchorh : this.dimensions.anchorh), this.dimensions.docscrolly); //position above anchor or window's top edge
		}
		menu.dropmenu.setcss({left:posx+'px', top:posy+'px', visibility:'visible'});
		if (this.effects.shadow.enabled) {
			menu.shadow.setcss({left:posx+linksMenu.effects.shadow.depth[0] + 'px', top:posy + linksMenu.effects.shadow.depth[1] + 'px', visibility:'visible'})
		}
	},

	revealmenu:function(menuid) {
		var menu = linksMenu.menusmap[menuid];
		this.setopacity(menu.dropmenu, 1);
		menu.dropmenu.style.filter = "";
	},

	setcss:function(param) {
		for (prop in param) {
			this.style[prop] = param[prop];
		}
	},

	hidemenu:function(menuid) {
		var menu = linksMenu.menusmap[menuid];
		menu.dropmenu.setcss({visibility:'hidden', left:0, top:0});
		menu.shadow.setcss({visibility:'hidden', left:0, top:0});
	},

	getElementsByClass:function(targetclass) {
		if (document.querySelectorAll)
			return document.querySelectorAll("."+targetclass);
		else{
			var classnameRE = new RegExp("(^|\\s+)"+targetclass+"($|\\s+)", "i"); //regular expression to screen for classname
			var pieces = [];
			var alltags = document.all ? document.all : document.getElementsByTagName("*");
			for (var i = 0; i < alltags.length; i++) {
				if (typeof alltags[i].className == "string" && alltags[i].className.search(classnameRE)!= -1)
					pieces[pieces.length] = alltags[i];
			}
			return pieces;
		}
	},

	addDiv:function(divid, divclass) {
		var el = document.createElement("div");
		if (divid)
			el.id = divid;
		el.className = divclass;
		document.body.appendChild(el);
		return el;
	},

	getmenuHTML:function(menuobj) {
		var menucontent = [];
		var frag = "";
		for (var i = 0; i < menuobj.items.length; i++) {
			frag += '<li><a href="' + menuobj.items[i][1] + '">' + menuobj.items[i][0] + '</a></li>\n';
			if (menuobj.items[i][2] == "efc" || i == menuobj.items.length - 1) {
				menucontent.push(frag);
				frag = "";
			}
		}
		return '<ul>\n' + menucontent.join('') + '\n</ul>';
	},

	addEvent:function(targetarr, functionref, tasktype) {
		if (targetarr.length > 0) {
			var target = targetarr.shift();
			if (target.addEventListener)
				target.addEventListener(tasktype, functionref, false);
			else if (target.attachEvent)
				target.attachEvent('on'+tasktype, function(){return functionref.call(target, window.event)});
			this.addEvent(targetarr, functionref, tasktype);
		}
	},

	setupmenu:function(targetclass, anchorobj, pos) {
		this.standardbody = (document.compatMode == "CSS1Compat") ? document.documentElement : document.body;
		var relattr = anchorobj.getAttribute("rel");
		dropmenuid = relattr.replace(/\[(\w+)\]/, '');
		var dropmenuvar = window[dropmenuid];
		var dropmenu = this.addDiv(null, dropmenuvar.divclass); //create and add main sub menu DIV
		dropmenu.innerHTML = this.getmenuHTML(dropmenuvar);
		var menu = this.menusmap[targetclass + pos] = {
			id: targetclass + pos,
			anchorobj: anchorobj,	
			dropmenu: dropmenu,
			revealtype: (relattr.length != dropmenuid.length && RegExp.$1 == "click") ? "click" : "mouseover",
			orientation: anchorobj.getAttribute("rev") == "lr" ? "lr" : "ud",
			shadow: this.addDiv(null, "anylinkshadow") //create and add corresponding shadow
		};
		menu.anchorobj._internalID = targetclass + pos;
		menu.anchorobj._isanchor = true;
		menu.dropmenu._internalID = targetclass + pos;
		menu.shadow._internalID = targetclass + pos;
		menu.dropmenu.setcss = this.setcss;
		menu.shadow.setcss = this.setcss;
		menu.shadow.setcss({width: menu.dropmenu.offsetWidth + "px", height:menu.dropmenu.offsetHeight + "px"});
		this.setopacity(menu.shadow, this.effects.shadow.opacity);
		this.addEvent([menu.anchorobj, menu.dropmenu, menu.shadow], function(e) { //MOUSEOVER event for anchor, dropmenu, shadow
			var menu = linksMenu.menusmap[this._internalID];
			if (this._isanchor && menu.revealtype=="mouseover" && !linksMenu.isContained(this, e)) { //event for anchor
				linksMenu.showmenu(menu.id);
			}
			else if (typeof this._isanchor=="undefined") { //event for drop down menu and shadow
				clearTimeout(menu.hidetimer);
			}
		}, "mouseover")
		this.addEvent([menu.anchorobj, menu.dropmenu, menu.shadow], function(e) { //MOUSEOUT event for anchor, dropmenu, shadow
			if (!linksMenu.isContained(this, e)){
				var menu = linksMenu.menusmap[this._internalID];
				menu.hidetimer = setTimeout(function(){linksMenu.hidemenu(menu.id)}, linksMenu.effects.delayhide);
			}
		}, "mouseout")
		this.addEvent([menu.anchorobj, menu.dropmenu], function(e){ //CLICK event for anchor, dropmenu
			var menu = linksMenu.menusmap[this._internalID];
			if (this._isanchor && menu.revealtype == "click") {
				if (menu.dropmenu.style.visibility == "visible")
					linksMenu.hidemenu(menu.id);
				else
					linksMenu.showmenu(menu.id);
				if (e.preventDefault)
					e.preventDefault();
				return false;
			}
			else
				menu.hidetimer = setTimeout(function(){linksMenu.hidemenu(menu.id)}, linksMenu.effects.delayhide);
		}, "click")
	},

	init:function(targetclass) {
		var anchors = this.getElementsByClass(targetclass);
		for (var i = 0; i < anchors.length; i++) {
			this.setupmenu(targetclass, anchors[i], i);
		}
	}
}