var persisteduls=new Object()
var ddtreemenu=new Object()

ddtreemenu.closefolder="images/closed.png" //set image path to "closed" folder image
ddtreemenu.openfolder="images/open.png" //set image path to "open" folder image

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

ddtreemenu.createTree=function(treeid, enablepersist, persistdays){
	var ultags=document.getElementById(treeid).getElementsByTagName("ul")
	if (typeof persisteduls[treeid]=="undefined")
		persisteduls[treeid]=(enablepersist==true && ddtreemenu.getCookie(treeid)!="")? ddtreemenu.getCookie(treeid).split(",") : ""
	for (var i=0; i<ultags.length; i++)
		ddtreemenu.buildSubTree(treeid, ultags[i], i)
	if (enablepersist==true){ //if enable persist feature
		var durationdays=(typeof persistdays=="undefined")? 1 : parseInt(persistdays)
		ddtreemenu.dotask(window, function(){
			ddtreemenu.rememberstate(treeid, durationdays)}, "unload") //save opened UL indexes on body unload
		}
	}

	ddtreemenu.buildSubTree=function(treeid, ulelement, index){
		ulelement.parentNode.className="submenu"
		if (typeof persisteduls[treeid]=="object"){ //if cookie exists (persisteduls[treeid] is an array versus "" string)
			if (ddtreemenu.searcharray(persisteduls[treeid], index)){
				ulelement.setAttribute("rel", "open")
				ulelement.style.display="block"
				ulelement.parentNode.style.backgroundImage="url("+ddtreemenu.openfolder+")"
			}
			else ulelement.setAttribute("rel", "closed")
		} //end cookie persist code
		else if (ulelement.getAttribute("rel")==null || ulelement.getAttribute("rel")==false) //if no cookie and UL has NO rel attribute explicted added by user
			ulelement.setAttribute("rel", "closed")
		else if (ulelement.getAttribute("rel")=="open") //else if no cookie and this UL has an explicit rel value of "open"
			ddtreemenu.expandSubTree(treeid, ulelement) //expand this UL plus all parent ULs (so the most inner UL is revealed!)
		
		ulelement.parentNode.onclick=function(e){
			var submenu=this.getElementsByTagName("ul")[0]
			if (submenu.getAttribute("rel")=="closed"){
				submenu.style.display="block"
				submenu.setAttribute("rel", "open")
				ulelement.parentNode.style.backgroundImage="url("+ddtreemenu.openfolder+")"
			}
			else if (submenu.getAttribute("rel")=="open"){
				submenu.style.display="none"
				submenu.setAttribute("rel", "closed")
				ulelement.parentNode.style.backgroundImage="url("+ddtreemenu.closefolder+")"
			}
			ddtreemenu.preventpropagate(e)
		}
		ulelement.onclick=function(e){
			ddtreemenu.preventpropagate(e)
		}
	}

	ddtreemenu.expandSubTree=function(treeid, ulelement){ //expand a UL element and any of its parent ULs	
		var rootnode=document.getElementById(treeid)
		var currentnode=ulelement
		currentnode.style.display="block"
		currentnode.parentNode.style.backgroundImage="url("+ddtreemenu.openfolder+")"
		while (currentnode!=rootnode){
			if (currentnode.tagName=="UL"){ //if parent node is a UL, expand it too
				currentnode.style.display="block"
				currentnode.setAttribute("rel", "open") //indicate it's open
				currentnode.parentNode.style.backgroundImage="url("+ddtreemenu.openfolder+")"
			}
			currentnode=currentnode.parentNode
		}
	}

	ddtreemenu.flatten=function(treeid, action){ //expand or contract all UL elements
		var ultags=document.getElementById(treeid).getElementsByTagName("ul")
		for (var i=0; i<ultags.length; i++){
			ultags[i].style.display=(action=="expand")? "block" : "none"
			var relvalue=(action=="expand")? "open" : "closed"
			ultags[i].setAttribute("rel", relvalue)
			ultags[i].parentNode.style.backgroundImage=(action=="expand")? "url("+ddtreemenu.openfolder+")" : "url("+ddtreemenu.closefolder+")"
		}
	}

	ddtreemenu.rememberstate=function(treeid, durationdays){ //store index of opened ULs relative to other ULs in Tree into cookie
		var ultags=document.getElementById(treeid).getElementsByTagName("ul")
		var openuls=new Array()

		for (var i=0; i<ultags.length; i++){
			if (ultags[i].getAttribute("rel")=="open") openuls[openuls.length]=i //save the index of the opened UL (relative to the entire list of ULs) as an array element
		}

		if (openuls.length==0) //if there are no opened ULs to save/persist
			openuls[0]="none open" //set array value to string to simply indicate all ULs should persist with state being closed
		ddtreemenu.setCookie(treeid, openuls.join(","), durationdays) //populate cookie with value treeid=1,2,3 etc (where 1,2... are the indexes of the opened ULs)
	}

////A few utility functions below//////////////////////

	ddtreemenu.getCookie=function(Name){ //get cookie value
		var re=new RegExp(Name+"=[^;]+", "i"); //construct RE to search for target name/value pair
		if (document.cookie.match(re)) //if cookie found
			return document.cookie.match(re)[0].split("=")[1] //return its value
		return ""
	}

	ddtreemenu.setCookie=function(name, value, days){ //set cookei value
		var expireDate = new Date()
		//set "expstring" to either future or past date, to set or delete cookie, respectively
		var expstring=expireDate.setDate(expireDate.getDate()+parseInt(days))
		document.cookie = name+"="+value+"; expires="+expireDate.toGMTString()+"; path=/";
	}

	ddtreemenu.searcharray=function(thearray, value){ //searches an array for the entered value. If found, delete value from array
		var isfound=false
		for (var i=0; i<thearray.length; i++){
			if (thearray[i]==value){
				isfound=true
				thearray.shift() //delete this element from array for efficiency sake
				break
			}
		}
		return isfound
	}

	ddtreemenu.preventpropagate=function(e){ //prevent action from bubbling upwards
		if (typeof e!="undefined") e.stopPropagation()
		else event.cancelBubble=true
	}

	ddtreemenu.dotask=function(target, functionref, tasktype){ //assign a function to execute to an event handler (ie: onunload)
		var tasktype=(window.addEventListener)? tasktype : "on"+tasktype
		if (target.addEventListener) target.addEventListener(tasktype, functionref, false)
		else if (target.attachEvent) target.attachEvent(tasktype, functionref)
	}