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

ddtreemenu.createTree=function(treeid, enablepersist, persistdays)
{
	var ultags=document.getElementById(treeid).getElementsByTagName("ul")

	for (var i=0; i<ultags.length; i++)
	{
		ddtreemenu.buildSubTree(treeid, ultags[i], i)
	}
}

ddtreemenu.buildSubTree=function(treeid, ulelement, index)
{
	ulelement.parentNode.className="submenu"
	
	if (ulelement.getAttribute("rel")==null || ulelement.getAttribute("rel")==false) 
	{
		ulelement.setAttribute("rel", "closed");
	}
	//else if no cookie and this UL has an explicit rel value of "open"
	else if (ulelement.getAttribute("rel")=="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.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)
	}
}