new Image().src = "./images/left_nav_closed.png";
new Image().src = "./images/left_nav_open.png";


var left_nav;
var left_nav_cats = [];

function initLeftNav() {

	left_nav = document.getElementById('left_nav').getElementsByTagName('ul');
	for(var ln=0; ln<left_nav.length; ln++) {
		if(left_nav[ln].className == "menu") {
			left_nav = left_nav[ln];
			break;
		}
	}
	
	var lis = left_nav.getElementsByTagName("li");

	for(var i=0; i<lis.length; i++) {
		if(lis[i].parentNode.className == "menu") left_nav_cats.push(lis[i]);
	}
	
	// open section containing current page
	var curSel = document.getElementById('left_nav_current');
	if(curSel) {
		var cur = curSel.parentNode.parentNode.parentNode;
		cur.className = cur.className.replace(/closed/,"open");
	}
	
	left_nav.onclick = left_nav_action;
}




function left_nav_action(evt) {
	
	evt = evt ? evt : window.event;
	var targ = evt.target ? evt.target : evt.srcElement;
	
	if(targ.nodeName != "A") return false;
	if(targ.parentNode.parentNode.className != "menu") return true;
	
	var open_close = targ.parentNode.className.search("open")+1 ? "closed" : "open";
	/*
	for(var k=0; k<left_nav_cats.length; k++) {
		left_nav_cats[k].className = "closed";
	}*/
	targ.parentNode.className = targ.parentNode.className.replace(/(open|closed)/,open_close);
	
	return false;
}