//** Chrome Drop Down Menu- Author: Dynamic Drive (http://www.dynamicdrive.com)

//** Updated: July 14th 06' to v2.0
//1) Ability to "left", "center", or "right" align the menu items easily, just by modifying the CSS property "text-align".
//2) Added an optional "swipe down" transitional effect for revealing the drop down menus.
//3) Support for multiple Chrome menus on the same page.

//** Updated: Nov 14th 06' to v2.01- added iframe shim technique

//** Updated: July 23rd, 08 to v2.4
//1) Main menu items now remain "selected" (CSS class "selected" applied) when user moves mouse into corresponding drop down menu. 
//2) Adds ability to specify arbitrary HTML that gets added to the end of each menu item that carries a drop down menu (ie: a down arrow image).
//3) All event handlers added to the menu are now unobstrusive, allowing you to define your own "onmouseover" or "onclick" events on the menu items.
//4) Fixed elusive JS error in FF that sometimes occurs when mouse quickly moves between main menu items and drop down menus

//** Updated: Oct 29th, 08 to v2.5 (only .js file modified from v2.4)
//1) Added ability to customize reveal animation speed (# of steps)
//2) Menu now works in IE8 beta2 (a valid doctype at the top of the page is required)

var cssdropdown = {
	disappeardelay: 250, //set delay in miliseconds before menu disappears onmouseout
	dropdownindicator: '<img src="down.gif" border="0" />', //specify full HTML to add to end of each menu item with a drop down menu
	enablereveal: [true, 8], //enable swipe effect? [true/false, steps (Number of animation steps. Integer between 1-20. Smaller=faster)]
	enableiframeshim: 1, //enable "iframe shim" in IE5.5 to IE7? (1=yes, 0=no)

	//No need to edit beyond here////////////////////////

	dropmenuobj: null, asscmenuitem: null, domsupport: document.all || document.getElementById, standardbody: null, iframeshimadded: false, revealtimers: {},

	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;
	},

	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
	},

	showmenu: function(dropmenu, e) {
		if (this.enablereveal[0]) {
			if (!dropmenu._trueheight || dropmenu._trueheight < 10)
				dropmenu._trueheight = dropmenu.offsetHeight
			clearTimeout(this.revealtimers[dropmenu.id])
			dropmenu.style.height = dropmenu._curheight = 0
			dropmenu.style.overflow = "hidden"
			dropmenu.style.visibility = "visible"
			this.revealtimers[dropmenu.id] = setInterval(function() { cssdropdown.revealmenu(dropmenu) }, 10)
		}
		else {
			dropmenu.style.visibility = "visible"
		}
		this.css(this.asscmenuitem, "selected", "add")
	},

	revealmenu: function(dropmenu, dir) {
		var curH = dropmenu._curheight, maxH = dropmenu._trueheight, steps = this.enablereveal[1]
		if (curH < maxH) {
			var newH = Math.min(curH, maxH)
			dropmenu.style.height = newH + "px"
			dropmenu._curheight = newH + Math.round((maxH - newH) / steps) + 1
		}
		else { //if done revealing menu
			dropmenu.style.height = "auto"
			dropmenu.style.overflow = "hidden"
			clearInterval(this.revealtimers[dropmenu.id])
		}
	},

	clearbrowseredge: function(obj, whichedge) {
		var edgeoffset = 0
		if (whichedge == "rightedge") {
			var windowedge = document.all && !window.opera ? this.standardbody.scrollLeft + this.standardbody.clientWidth - 15 : window.pageXOffset + window.innerWidth - 15
			var dropmenuW = this.dropmenuobj.offsetWidth
			if (windowedge - this.dropmenuobj.x < dropmenuW)  //move menu to the left?
				edgeoffset = dropmenuW - obj.offsetWidth
		}
		else {
			var topedge = document.all && !window.opera ? this.standardbody.scrollTop : window.pageYOffset
			var windowedge = document.all && !window.opera ? this.standardbody.scrollTop + this.standardbody.clientHeight - 15 : window.pageYOffset + window.innerHeight - 18
			var dropmenuH = this.dropmenuobj._trueheight
			if (windowedge - this.dropmenuobj.y < dropmenuH) { //move up?
				edgeoffset = dropmenuH + obj.offsetHeight
				if ((this.dropmenuobj.y - topedge) < dropmenuH) //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.hidemenu() //hide menu
		this.clearhidemenu()
		this.dropmenuobj = document.getElementById(dropmenuID) //reference drop down menu
		this.asscmenuitem = obj //reference associated menu item
		this.showmenu(this.dropmenuobj, e)
		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.positionshim() //call iframe shim function
	},

	positionshim: function() { //display iframe shim function
		if (this.iframeshimadded) {
			if (this.dropmenuobj.style.visibility == "visible") {
				this.shimobject.style.width = this.dropmenuobj.offsetWidth + "px"
				this.shimobject.style.height = this.dropmenuobj._trueheight + "px"
				this.shimobject.style.left = parseInt(this.dropmenuobj.style.left) + "px"
				this.shimobject.style.top = parseInt(this.dropmenuobj.style.top) + "px"
				this.shimobject.style.display = "block"
			}
		}
	},

	hideshim: function() {
		if (this.iframeshimadded)
			this.shimobject.style.display = 'none'
	},

	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
	},

	dynamichide: function(m, e) {
		if (!this.isContained(m, e)) {
			this.delayhidemenu()
		}
	},

	delayhidemenu: function() {
		this.delayhide = setTimeout("cssdropdown.hidemenu()", this.disappeardelay) //hide menu
	},

	hidemenu: function() {
		this.css(this.asscmenuitem, "selected", "remove")
		this.dropmenuobj.style.visibility = 'hidden'
		this.dropmenuobj.style.left = this.dropmenuobj.style.top = "-1000px"
		this.hideshim()
	},

	clearhidemenu: function() {
		if (this.delayhide != "undefined")
			clearTimeout(this.delayhide)
	},

	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) });
	},

	startchrome: function() {
		if (!this.domsupport)
			return
		this.standardbody = (document.compatMode == "CSS1Compat") ? document.documentElement : document.body
		for (var ids = 0; ids < arguments.length; ids++) {
			var menuitems = document.getElementById(arguments[ids]).getElementsByTagName("a")
			for (var i = 0; i < menuitems.length; i++) {
				if (menuitems[i].getAttribute("rel")) {
					var relvalue = menuitems[i].getAttribute("rel")
					var asscdropdownmenu = document.getElementById(relvalue)
					this.addEvent(asscdropdownmenu, function() { cssdropdown.clearhidemenu() }, "mouseover")
					this.addEvent(asscdropdownmenu, function(e) { cssdropdown.dynamichide(this, e) }, "mouseout")
					this.addEvent(asscdropdownmenu, function() { cssdropdown.delayhidemenu() }, "click")
					try {
						menuitems[i].innerHTML = menuitems[i].innerHTML + " " + this.dropdownindicator
					} catch (e) { }
					this.addEvent(menuitems[i], function(e) { //show drop down menu when main menu items are mouse over-ed
						if (!cssdropdown.isContained(this, e)) {
							var evtobj = window.event || e
							cssdropdown.dropit(this, evtobj, this.getAttribute("rel"))
						}
					}, "mouseover")
					this.addEvent(menuitems[i], function(e) { cssdropdown.dynamichide(this, e) }, "mouseout") //hide drop down menu when main menu items are mouse out
					this.addEvent(menuitems[i], function() { cssdropdown.delayhidemenu() }, "click") //hide drop down menu when main menu items are clicked on
				}
			} //end inner for
		} //end outer for
		if (this.enableiframeshim && document.all && !window.XDomainRequest && !this.iframeshimadded) { //enable iframe shim in IE5.5 thru IE7?
			document.write('<IFRAME id="iframeshim" src="about:blank" frameBorder="0" scrolling="no" style="left:0; top:0; position:absolute; display:none;z-index:90; background: transparent;"></IFRAME>')
			this.shimobject = document.getElementById("iframeshim") //reference iframe object
			this.shimobject.style.filter = 'progid:DXImageTransform.Microsoft.Alpha(style=0,opacity=0)'
			this.iframeshimadded = true
		}
	} //end startchrome

}