function tree_expand(item, path)
{
	item.getElementsByTagName("div")[0].style.display = "block";
	item.getElementsByTagName("img")[0].src = path + "minus.gif";	
}

function tree_collapse(item, path)
{
	item.getElementsByTagName("div")[0].style.display = "none";
	item.getElementsByTagName("img")[0].src = path + "plus.gif";
}

function tree_switch_item(item, item_id, path, def)
{	
	tree_initialize(path);
	try
	{
		visibility = eval(item_id);		
	}
	catch(e)
	{
		eval(item_id + " = " + def);
		visibility = def;
	}
		
	if (visibility)
	{
		tree_collapse(item, path);
	}
	else
	{
		tree_expand(item, path);
	}	
	eval(item_id + " = " + (1 - visibility));
}

var tree_initialized = 0;
function tree_initialize(path)
{
	if (tree_initialized)
	{
		return;
	}

	var list = new Array('plus', 'minus', 'none');

	for (_item in list)
	{
		img = new Image();
		img.src = path + list + '.gif';
	}
	tree_initialized = 1;
}

function setActive(element)
{
	try {
	var curr = document.getElementById(currentActive);
	curr.className = '';
	} catch(e) {}

	element.className = 'selected';
	currentActive = element.id;
}