var persisteduls=new Object()
var ddtreemenu=new Object()
var previousMenuOpened=0
var previousSubMenuOpened=0

ddtreemenu.openedfolder_hl="images/nav/open_hilight.gif" //set highlighting background image to use when folder is open
ddtreemenu.closefolder="images/nav/closed_hilight.gif" //set closed folder image to use when folder is closed
ddtreemenu.openedfolder_bh="images/nav/open_bh.gif" //set highlighting background image to use when folder is open w. no hilight

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", "opened")
			ulelement.style.display="block"
			ulelement.parentNode.style.backgroundImage="url("+ddtreemenu.openedfolder_bh+")"
		}
		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")=="stay") //else if no cookie and this UL has an explicit rel value of "opened"
		ddtreemenu.expandSubTree(treeid, ulelement) //expand this UL plus all parent ULs (so the most inner UL is revealed!)
		
	// Clicking on parent event handler
	ulelement.parentNode.onclick=function(e)
	{
		var submenu=this.getElementsByTagName("ul")[0]
		
		// Collapse previously opened menu item
		if( previousMenuOpened != 0 && previousSubMenuOpened != submenu)
		{
			previousSubMenuOpened.style.display="none"
			previousSubMenuOpened.setAttribute("rel", "closed")
			previousMenuOpened.style.color="#FFFFFF"
			previousMenuOpened.style.backgroundImage="url("+ddtreemenu.closefolder+")"
			previousMenuOpened = 0
		}		
			// If closed, open ... If opened, then close
		if (submenu.getAttribute("rel")=="closed") 
		{
			// Open
			submenu.style.display="block"
			submenu.setAttribute("rel", "opened")
			
			ulelement.parentNode.style.backgroundImage="url("+ddtreemenu.openedfolder_hl+")"
			ulelement.parentNode.style.color="#FFFFFF"
			previousMenuOpened=ulelement.parentNode
			previousSubMenuOpened = submenu
		}
		else if(submenu.getAttribute("rel")!="stay")
		{
			// Close
			submenu.style.display="none"
			submenu.setAttribute("rel", "closed")
			ulelement.parentNode.style.backgroundImage="url("+ddtreemenu.closefolder+")"
			ulelement.parentNode.style.color="#FFFFFF"
			previousSubMenuOpened = submenu			
			
		}	
	   	
		ddtreemenu.preventpropagate(e)
	}

	// Clicking on element event handler
	ulelement.onclick=function(e)
	{
		ddtreemenu.preventpropagate(e)
	}

}

//expand a UL element and any of its parent ULs
ddtreemenu.expandSubTree=function(treeid, ulelement)
{ 

	var rootnode=document.getElementById(treeid)
	var currentnode=ulelement
	
	currentnode.style.display="block"
	currentnode.parentNode.style.backgroundImage="url("+ddtreemenu.openedfolder_hl+")"
	currentnode.parentNode.style.color="#FFFFFF"
	
	while (currentnode!=rootnode)
	{
		//if parent node is a UL, expand it too
		if (currentnode.tagName=="UL")
		{ 
			currentnode.style.display="block"
			currentnode.setAttribute("rel", "stay") //indicate it's staying open
			currentnode.parentNode.style.backgroundImage="url("+ddtreemenu.openedfolder_hl+")"
		}
		
		currentnode=currentnode.parentNode


	}
}

//expand or contract all UL elements
ddtreemenu.flatten=function(treeid, action)
{ 
	var ultags=document.getElementById(treeid).getElementsByTagName("ul")
	
	for (var i=1; i<ultags.length; i++)
	{
		//ultags[i].style.display=(action=="expand")? "block" : "none"
		var relvalue=""
		if(action=="expand"){
			ultags[i].style.display="block"
			relvalue="opened"
			ultags[i].parentNode.style.backgroundImage="url("+ddtreemenu.openedfolder_bh+")"
			ultags[i].parentNode.style.color="#FFFFFF"
			ultags[i].setAttribute("rel", relvalue)			
		}
		else
		{
			ultags[i].style.display="none"
			relvalue="closed"
			ultags[i].parentNode.style.backgroundImage="url("+ddtreemenu.closefolder+")"
			ultags[i].parentNode.style.color="#000000"
			ultags[i].setAttribute("rel", relvalue)
		}
		//var relvalue=(action=="expand")? "opened" : "closed" 

		//ultags[i].setAttribute("rel", relvalue)
		
		//ultags[i].parentNode.style.backgroundImage=(action=="expand")? "url("+ddtreemenu.openedfolderhighlight+")" : "url("+ddtreemenu.closedfolder+")"
		
	/*	if(action=="expand"){
			ultags[i].parentNode.style.backgroundImage="url("+ddtreemenu.openedfolder_bh+")"
			ultags[i].parentNode.style.color="#FFFFFF"
				
		}
		else{
			ultags[i].parentNode.style.backgroundImage="url("+ddtreemenu.closefolder+")"
			ultags[i].parentNode.style.color="#FFFFFF"
				
		}*/

	}
}

//store index of opened ULs relative to other ULs in Tree into cookie
ddtreemenu.rememberstate=function(treeid, durationdays)
{ 
	var ultags=document.getElementById(treeid).getElementsByTagName("ul")
	var openuls=new Array()
	
	for (var i=0; i<ultags.length; i++)
	{
		if (ultags[i].getAttribute("rel")=="opened")
			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 opened" //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)
}

//get cookie value
ddtreemenu.getCookie=function(Name)
{
	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 ""
}

//set cookei value
ddtreemenu.setCookie=function(name, value, days)
{ 
	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=/";
}

//searches an array for the entered value. If found, delete value from array
ddtreemenu.searcharray=function(thearray, value)
{ 
	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
}

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

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