function initNavTree(){
	var trunkElements = document.getElementById('navTree').childNodes;
	var enterAElement = document.getElementById('enter');
	if (enterAElement) 
		enterAElement.onclick = showLoginForm;
	document.getElementById('closeLoginForm').onclick = hideLoginForm;
	
	for (var i = 0; i < trunkElements.length; i++){
		if (trunkElements[i].className == 'trunk' && trunkElements[i].id != 'final_trunk'){
			var aElement = document.createElement('a');
			//aElement.appendChild(document.createTextNode('+'));
			aElement.href = '#';
			aElement.onclick = showBranch;
			aElement.className = 'pointer';
			trunkElements[i].getElementsByTagName('li').item(0).appendChild(aElement);
		}
	}
	document.body.onclick = hideElements;
}

function showBranch(e){
	var branchElement;
	if (e){
		e.stopPropagation();
		branchElement = e.target.parentNode.nextSibling.nextSibling;
	}
	else if (event.cancelBubble == false){
		event.cancelBubble = true;
		branchElement = event.srcElement.parentNode.nextSibling;
	}
	if (branchElement.style.visibility == 'visible')
		branchElement.style.visibility = 'hidden'; 
	else{
		hideElements();
		branchElement.style.visibility = 'visible'; 
	}
}
function hideElements(e){
	var branchElements = document.getElementById('navTree').getElementsByTagName('li');
	for (i = 0; i < branchElements.length; i++){
		if (branchElements[i].className == 'branch')
			branchElements[i].style.visibility = 'hidden';
	}
	//document.getElementById("loginForm").style.visibility = "hidden";
}
function showLoginForm(e){
	var loginFormElement = document.getElementById("loginForm");
	if (e){
		e.stopPropagation();
	}
	else if (event.cancelBubble == false){
		event.cancelBubble = true;
	}
	loginFormElement.style.visibility = "visible";
	document.getElementById("curtain").style.visibility = "visible"
	document.getElementById('user').focus();
	
	return false;
}
function hideLoginForm() {
	document.getElementById("loginForm").style.visibility = "hidden"
	document.getElementById("curtain").style.visibility = "hidden"
}