function tree(id, pbId) {
	var element = document.getElementById(id)

	function hasClass(elem, className) {
		return new RegExp("(^|\\s)"+className+"(\\s|$)").test(elem.className)
	}

	function toggleNode(node) {
		var newClass = hasClass(node, 'ExpandOpen') ? 'ExpandClosed' : 'ExpandOpen'
		var re =  /(^|\s)(ExpandOpen|ExpandClosed)(\s|$)/
		node.className = node.className.replace(re, '$1'+newClass+'$3')
	}

	function load(node) {

		function showLoading(on) {
			var expand = node.getElementsByTagName('DIV')[0]
			expand.className = on ? 'ExpandLoading' : 'Expand'
		}

		function show_date(responseText, cartParams) {
			node.getElementsByTagName('UL')[0].innerHTML = responseText;
			node.isLoaded = true;
			toggleNode(node);
			showLoading(false)
		}

		showLoading(true)

		url = "./block.php";
		url += "?pb_id="+pbId;
		url += "&type="+id;
		url += "&parent_id="+node.id;

		callAjax(url, show_date, '');
	}

	element.onclick = function(event) {
		event = event || window.event
		var clickedElem = event.target || event.srcElement

		if (!hasClass(clickedElem, 'Expand')) {
			return
		}

		var node = clickedElem.parentNode
		if (hasClass(node, 'ExpandLeaf')) {
			return
		}

		if (node.isLoaded || node.getElementsByTagName('LI').length) {
			toggleNode(node);
			return;
		}


		if (node.getElementsByTagName('LI').length) {
			toggleNode(node);
			return;
		}

		load(node)
	}
}