//Chrome Drop Down Menu- Author: Dynamic Drive (http://www.dynamicdrive.com)
//Last updated: Jan 1st, 06'

var cssdropdown = {

	disappeardelay: 250, // set delay in miliseconds before menu disappears onmouseout
	dropImgPrefix:  "",
	dropmenuobj:    null, 
	ie:             document.all, 
	firefox:        document.getElementById && !document.all,
	lastmenu:       "",
	imgPrefix:      "nav_",
	imgLocation:    "/files",
	
	setImagePrefix: function(prefix) {
		this.imgPrefix = prefix;
	},

	setImageLocation: function(location) {
		this.imgLocation = location;
	},
		
	getposOffset: function(what, offsettype)
	{
		var totaloffset = (offsettype=="left")? what.offsetLeft : what.offsetTop;
		var parentEl = what.offsetParent;
		while (parentEl != null){
			totaloffset = (offsettype == "left")? totaloffset+parentEl.offsetLeft : totaloffset+parentEl.offsetTop;
			parentEl=parentEl.offsetParent;
		}
		return totaloffset;
	},

	showhide: function(obj, e, visible, hidden)
	{
		if (this.ie || this.firefox)
			this.dropmenuobj.style.left=this.dropmenuobj.style.top="-500px"
		if (e.type=="click" && obj.visibility==hidden || e.type=="mouseover")
			obj.visibility=visible
		else if (e.type=="click")
			obj.visibility=hidden
	},

	iecompattest: function() {
		return (document.compatMode && document.compatMode!="BackCompat")? document.documentElement : document.body
	},

	clearbrowseredge: function(obj, whichedge)
	{
		var edgeoffset=0
		if (whichedge=="rightedge"){
		var windowedge = this.ie && !window.opera? this.iecompattest().scrollLeft+this.iecompattest().clientWidth-15 : window.pageXOffset+window.innerWidth-15
		this.dropmenuobj.contentmeasure=this.dropmenuobj.offsetWidth
		if (windowedge-this.dropmenuobj.x < this.dropmenuobj.contentmeasure)  //move menu to the left?
			edgeoffset=this.dropmenuobj.contentmeasure-obj.offsetWidth
		}
		else{
			var topedge=this.ie && !window.opera? this.iecompattest().scrollTop : window.pageYOffset
			var windowedge=this.ie && !window.opera? this.iecompattest().scrollTop+this.iecompattest().clientHeight-15 : window.pageYOffset+window.innerHeight-18
			this.dropmenuobj.contentmeasure=this.dropmenuobj.offsetHeight
			if (windowedge-this.dropmenuobj.y < this.dropmenuobj.contentmeasure){ //move up?
				edgeoffset=this.dropmenuobj.contentmeasure+obj.offsetHeight
				if ((this.dropmenuobj.y-topedge)<this.dropmenuobj.contentmeasure) //up no good either?
					edgeoffset=this.dropmenuobj.y+obj.offsetHeight-topedge
			}
		}
		return edgeoffset
	},

	dropit: function(obj, e, dropmenuID)
	{
		if (this.dropmenuobj!=null) //hide previous menu
			this.dropmenuobj.style.visibility="hidden"
			
		this.clearhidemenu();
		if (this.ie || this.firefox){
			obj.onmouseout = function() {
				cssdropdown.delayhidemenu(dropmenuID);
			}
			this.dropmenuobj=document.getElementById(dropmenuID)
			this.dropmenuobj.onmouseover=function(){cssdropdown.clearhidemenu()}
			this.dropmenuobj.onmouseout=function(){cssdropdown.dynamichide(e, dropmenuID)}
			this.dropmenuobj.onclick=function(){cssdropdown.delayhidemenu()}
			this.showhide(this.dropmenuobj.style, e, "visible", "hidden")
			this.dropmenuobj.x=this.getposOffset(obj, "left")
			this.dropmenuobj.y=this.getposOffset(obj, "top")
			this.dropmenuobj.style.left=this.dropmenuobj.x-this.clearbrowseredge(obj, "rightedge")+"px"
			this.dropmenuobj.style.top=this.dropmenuobj.y-this.clearbrowseredge(obj, "bottomedge")+obj.offsetHeight+1+"px"
		}
		this.lastmenu = dropmenuID;
	},

	contains_firefox: function(a, b) 
	{
		while (b.parentNode)
			if ((b = b.parentNode) == a) return true;
		return false;
	},

	dynamichide: function(e, menuId)
	{
		var evtobj=window.event? window.event : e;
		if (this.ie&&!this.dropmenuobj.contains(evtobj.toElement))
			this.delayhidemenu(menuId)
		else if (this.firefox&&e.currentTarget!= evtobj.relatedTarget && !this.contains_firefox(evtobj.currentTarget, evtobj.relatedTarget))
			this.delayhidemenu(menuId)
	},

	delayhidemenu: function(menuId) {
		this.delayhide = setTimeout("cssdropdown.__hideMenu('"+menuId+"')",this.disappeardelay)
	},
	
	clearhidemenu:function() {
		if (this.delayhide!="undefined")
			clearTimeout(this.delayhide);
		if (this.lastmenu != "")
			changeImages(this.imgPrefix+this.lastmenu, this.imgLocation+"/"+this.imgPrefix+this.lastmenu+".gif");
	},
	
	__hideMenu:function(menuId) 
	{
		cssdropdown.dropmenuobj.style.visibility='hidden';
		changeImages(this.imgPrefix+menuId, this.imgLocation+"/"+this.imgPrefix+menuId+".gif");
	}
};