function getTarget(e) {
	var targ;
	if (!e){
		var e = window.event;
	}
	if (e.target){
		targ = e.target;
	}
	else if (e.srcElement){
		targ = e.srcElement;
	}
	if (targ.nodeType == 3) { // defeat Safari bug
		targ = targ.parentNode;
	}
	return targ;
}

 
function switchNavTree(item){
	var li = item;
	while (li.nodeName != 'LI'){
		li = li.parentNode;
	}
	var situation = li.className;
	var newsituation;
// 	if (set != null) {
		if (situation == 'treeopen'){
			newsituation = 'treeclosed';
		} else if(situation == 'treeclosed'){
			newsituation = 'treeopen';
		}
// 	} else {
// 		newsituation = set;
// 	}
	li.className = newsituation;
	for (var i = 0 ; i < li.childNodes.length ; i ++ ){
		if (li.childNodes[i].nodeName == 'UL') {
			if (newsituation == 'treeopen'){
				li.childNodes[i].style.display = 'block';
			} else if(newsituation == 'treeclosed'){
				li.childNodes[i].style.display = 'none';
			}
		}
	}
}