//** 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, 5], //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

}