var menu={
	hideinterval: 200, //delay in milliseconds before sub menu(s) disappears onmouseout.
	httpsiframesrc: "blank.htm", // For running menu in https sites
	topmenuids: [], //array containing ids of all the primary menus on the page
	topitems: {}, //object array containing all top menu item links
	subuls: {}, //object array containing all ULs
	topitemsindex: -1,
	ulindex: -1,
	hidetimers: {}, //object array timer
	shimadded: false,

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

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

	getwindowsize:function(){
		if (window.innerWidth){
			this.docwidth = window.innerWidth - 10;
		}else{
			this.docwidth = this.standardbody.clientWidth - 10
		}
		if (window.innerHeight){
			this.docheight = window.innerHeight - 15;
		}else{
			this.docheight = this.standardbody.clientHeight - 15 
		}
	},

	gettopitemsdimensions:function(){
		for (var m = 0; m < this.topmenuids.length; m++){
			var topmenuid = this.topmenuids[m]
			for (var i = 0; i < this.topitems[topmenuid].length; i++){
				var header = this.topitems[topmenuid][i]
				var submenu = document.getElementById(header.getAttribute('rel'))
				header._dimensions = {w:header.offsetWidth, h:header.offsetHeight, submenuw:submenu.offsetWidth, submenuh:submenu.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
	},

	css:function(el, targetclass, action){
		var needle=new RegExp("(^|\\s+)"+targetclass+"($|\\s+)", "ig")
		if (action=="check")
			return needle.test(el.className)
		else if (action=="remove")
			el.className=el.className.replace(needle, "")
		else if (action=="add" && !needle.test(el.className))
			el.className+=" "+targetclass
	},

	addshimmy:function(target){
		var shim=(!window.opera)? document.createElement("iframe") : document.createElement("div") //Opera 9.24 doesnt seem to support transparent IFRAMEs
		shim.className="iframeshim"
		shim.setAttribute("src", location.protocol=="https:"? this.httpsiframesrc : "about:blank")
		shim.setAttribute("frameborder", "0")
		target.appendChild(shim)
		try{
			shim.style.filter='progid:DXImageTransform.Microsoft.Alpha(style=0,opacity=0)'
		}
		catch(e){}
		return shim
	},

	positionshim:function(header, submenu, scrollX, scrollY){
		if (header._istoplevel){
			var scrollY=window.pageYOffset? window.pageYOffset : this.standardbody.scrollTop
			var topgap=header._offsets.top-scrollY
			var bottomgap=scrollY+this.docheight-header._offsets.top-header._dimensions.h
			if (topgap>0){
				this.shimmy.topshim.style.left=scrollX+"px"
				this.shimmy.topshim.style.top=scrollY+"px"
				this.shimmy.topshim.style.width="99%"
				this.shimmy.topshim.style.height=topgap+"px" //distance from top window edge to top of menu item
			}
			if (bottomgap>0){
				this.shimmy.bottomshim.style.left=scrollX+"px"
				this.shimmy.bottomshim.style.top=header._offsets.top + header._dimensions.h +"px"
				this.shimmy.bottomshim.style.width="99%"
				this.shimmy.bottomshim.style.height=bottomgap+"px" //distance from bottom of menu item to bottom window edge
			}
		}
	},

	hideshim:function(){
		this.shimmy.topshim.style.width=this.shimmy.bottomshim.style.width=0
		this.shimmy.topshim.style.height=this.shimmy.bottomshim.style.height=0
	},

	buildmenu:function(mainmenuid, header, submenu, submenupos, istoplevel){
		header._master=mainmenuid //Indicate which top menu this header is associated with
		header._pos=submenupos //Indicate pos of sub menu this header is associated with
		header._istoplevel=istoplevel
		if (istoplevel){
			this.addEvent(header, function(e){
			menu.hidemenu(menu.subuls[this._master][parseInt(this._pos)])
			}, "click")
		}
		this.subuls[mainmenuid][submenupos]=submenu
		header._dimensions={w:header.offsetWidth, h:header.offsetHeight, submenuw:submenu.offsetWidth, submenuh:submenu.offsetHeight}
		this.getoffsetof(header)
		submenu.style.left=0
		submenu.style.top=0
		submenu.style.visibility="hidden"
		this.addEvent(header, function(e){ //mouseover event
			if (!menu.isContained(this, e)){
				if (typeof menu.hidetimers[this._master][parseInt(this._pos)]!="undefined")
					clearTimeout(menu.hidetimers[this._master][parseInt(this._pos)])
				if (this._istoplevel)
					menu.css(this, "selected", "add")
				var submenu=menu.subuls[this._master][parseInt(this._pos)]
				menu.getoffsetof(header)
				var scrollX=window.pageXOffset? window.pageXOffset : menu.standardbody.scrollLeft
				var scrollY=window.pageYOffset? window.pageYOffset : menu.standardbody.scrollTop
				var submenurightedge=this._offsets.left + this._dimensions.submenuw
				var submenubottomedge=this._offsets.top + this._dimensions.submenuh
				//Sub menu starting left position
				var menuleft=(this._istoplevel? this._offsets.left : this._dimensions.w)
				if (submenurightedge-scrollX>menu.docwidth){
					menuleft+= -this._dimensions.submenuw + this._dimensions.w
				}
				submenu.style.left=menuleft+"px"
				//Sub menu starting top position
				var menutop=(this._istoplevel? this._offsets.top + this._dimensions.h : this.offsetTop)
				submenu.style.top=menutop+"px"			
				menu.positionshim(this, submenu, scrollX, scrollY)
				submenu.style.visibility="visible"
			}
		}, "mouseover")
		this.addEvent(header, function(e){ //mouseout event
			if (this._istoplevel){
				var submenu=menu.subuls[this._master][parseInt(this._pos)]
				if (!menu.isContained(this, e) && !menu.isContained(submenu, e)) //hide drop down ul if mouse moves out of menu bar item but not into drop down ul itself
					menu.hidemenu(submenu)
			}
			else if (!this._istoplevel && !menu.isContained(this, e)){
				var headerlist=this
				menu.hidetimers[this._master][parseInt(this._pos)]=setTimeout(function(){
					var submenu=menu.subuls[headerlist._master][parseInt(headerlist._pos)]
					menu.hidemenu(submenu)
				}, menu.hideinterval)
			}
		}, "mouseout")
	},
	
	hidemenu:function(submenu){
		if (typeof submenu._pos!="undefined"){ //if submenu is outermost UL drop down menu
			this.css(this.topitems[submenu._master][parseInt(submenu._pos)], "selected", "remove")
			this.hideshim()
		}
		submenu.style.left=0
		submenu.style.top="-1000px"
		submenu.style.visibility="hidden"
	},
	
	
	addEvent:function(target, functionref, tasktype) {
		if (target.addEventListener)
			target.addEventListener(tasktype, functionref, false);
		else if (target.attachEvent)
			target.attachEvent('on'+tasktype, function(){return functionref.call(target, window.event)});
	},

	init:function(mainmenuid){
		this.standardbody=(document.compatMode=="CSS1Compat")? document.documentElement : document.body
		this.topitemsindex=-1
		this.ulindex=-1
		this.topmenuids.push(mainmenuid)
		this.topitems[mainmenuid]=[] //declare array on object
		this.subuls[mainmenuid]=[] //declare array on object
		this.hidetimers[mainmenuid]=[] //declare array on object
		if (!this.shimadded){
			this.shimmy={}
			this.shimmy.topshim=this.addshimmy(document.body) //create top iframe shim obj
			this.shimmy.bottomshim=this.addshimmy(document.body) //create bottom iframe shim obj
			this.shimadded=true
		}
		var menubar=document.getElementById(mainmenuid)
		var alllinks=menubar.getElementsByTagName("a")
		this.getwindowsize()
		for (var i=0; i<alllinks.length; i++){
			if (alllinks[i].getAttribute('rel')){
				this.topitemsindex++
				this.ulindex++
				var menuitem=alllinks[i]
				this.topitems[mainmenuid][this.topitemsindex]=menuitem //store ref to main menu links
				var dropul=document.getElementById(menuitem.getAttribute('rel'))
				dropul.style.zIndex=2000 //give drop down menus a high z-index
				dropul._master=mainmenuid  //Indicate which main menu this main UL is associated with
				dropul._pos=this.topitemsindex //Indicate which main menu item this main UL is associated with
				this.addEvent(dropul, function(){menu.hidemenu(this)}, "click")
				this.buildmenu(mainmenuid, menuitem, dropul, this.ulindex, true) //build top level menu
				this.addEvent(dropul, function(e){ //hide menu if mouse moves out of main UL element into open space
					if (!menu.isContained(this, e) && !menu.isContained(menu.topitems[this._master][parseInt(this._pos)], e)){
						var dropul=this
						menu.hidetimers[this._master][parseInt(this._pos)]=setTimeout(function(){
							menu.hidemenu(dropul)
						}, menu.hideinterval)
					}
				}, "mouseout")
				var subuls=dropul.getElementsByTagName("ul")
				for (var c=0; c<subuls.length; c++){
					this.ulindex++
					var parentli=subuls[c].parentNode
					this.buildmenu(mainmenuid, parentli, subuls[c], this.ulindex, false) //build sub level menus
				}
			}
		} //end for loop
		this.addEvent(window, function(){menu.getwindowsize(); menu.gettopitemsdimensions()}, "resize")
	},
	
	setup:function(mainmenuid){
		this.addEvent(window, function(){menu.init(mainmenuid)}, "load")
	}
}