Array.prototype.indexOf = IndexOf;

//Toggles between two classes for an element
function ToggleClass(element, firstClass, secondClass, event)
{
	event.cancelBubble = true;

	var classes = element.className.split(" ");
	var firstClassIndex = classes.indexOf(firstClass);
	var secondClassIndex = classes.indexOf(secondClass);

	if (firstClassIndex == -1 && secondClassIndex == -1)
	{
		classes[classes.length] = firstClass;}
	else if (firstClassIndex!= -1)
	{
		classes[firstClassIndex] = secondClass;
	}
	else
	{
		classes[secondClassIndex] = firstClass;
	}
	element.className = classes.join(" ");
}

//Finds the index of an item in an array
function IndexOf(item)
{
	for (var i=0; i < this.length; i++)
	{
		if (this[i] == item)
		{
			return i;
		}
	}
	return -1;
}

//The toggle event handler for each expandable/collapsable node
//- Note that this also exists to prevent any IE memory leaks
//(due to circular references caused by this)
function ToggleNodeStateHandler(event)
{
	ToggleClass(this, "Collapsed", "Expanded", (event == null)? window.event : event);
}

//Prevents the onclick event from bubbling up to parent elements
function PreventBubbleHandler(event)
{
	if (!event) 
		event = window.event;

	event.cancelBubble = true;
}

//Adds the relevant onclick handlers for the nodes in the tree view
function Setuptreeview(elementId)
{
	var tree = document.getElementById(elementId);
	var treeElements = tree.getElementsByTagName("li");

	for (var i=0; i < treeElements.length; i++)
	{
		if (treeElements[i].getElementsByTagName("ul").length > 0)
		{
			treeElements[i].onclick = ToggleNodeStateHandler;
		}
		else
		{
			treeElements[i].onclick = PreventBubbleHandler;
		}
	}
}


function ExpandTree(pLinkIdToShow)
{
	var loLink = document.getElementById(pLinkIdToShow);

	if (loLink)
	{
		var currentObject = loLink;
		while (currentObject.tagName != "BODY")
		{
			if (currentObject.tagName == "LI")
				currentObject.className = "Expanded";
			currentObject = currentObject.parentNode;
		}
	}
}