function addEvent(obj,type,fn) {
	if(obj) {
		if (obj.addEventListener) {
			obj.addEventListener( type, fn, false );
			EventCache.add(obj, type, fn);
		}
		else if (obj.attachEvent) {
			obj["e"+type+fn] = fn;
			obj[type+fn] = function() { obj["e"+type+fn]( window.event ); }
			obj.attachEvent( "on"+type, obj[type+fn] );
			EventCache.add(obj, type, fn);
		}
		else {
			obj["e"+type+fn] = fn;
			obj["on"+type] = obj["e"+type+fn];
		}
	}
}

var EventCache = function(){
	var listEvents = [];
	return {
		listEvents : listEvents,
		add : function(node, sEventName, fHandler){
			listEvents.push(arguments);
		},
		flush : function(){
			var i, item;
			for(i = listEvents.length - 1; i >= 0; i = i - 1){
				item = listEvents[i];
				if(item[0].removeEventListener){
					item[0].removeEventListener(item[1], item[2], item[3]);
				};
				if(item[1].substring(0, 2) != "on"){
					item[1] = "on" + item[1];
				};
				if(item[0].detachEvent){
					item[0].detachEvent(item[1], item[2]);
				};
				item[0][item[1]] = null;
			};
		}
	};
}();
addEvent(window,'unload',EventCache.flush); // fixes IE memory leak issues

function preventDefault(e) {
	if (e.preventDefault) {
		e.preventDefault();
	} else {
		e.returnValue = false;
	}
}

var navToggle = new Array();
function initOn() {
	if(document.getElementById && document.getElementsByTagName) {
		var navLinks = document.getElementById("nav").getElementsByTagName("a");
		for (var i=0, j=navLinks.length; i < j; i++) {
			if(navLinks[i].href.indexOf("#") != -1) {
				navToggle[navToggle.length] = navLinks[i];
				addEvent(navLinks[i],'click',setOn);
			}
		}
		navLinks[1].className="on"; // portfolio
		document.body.className = "js";
	}
}

function setOn(e) {
	for (var i=0, j=navToggle.length; i < j; i++) {
		var linkTarget = navToggle[i].href.substring(navToggle[i].href.indexOf("#")+1);
		if(navToggle[i].href == this.href) {
			navToggle[i].className = "on";
			document.getElementById(linkTarget).style.display = "block";
		} else {
			navToggle[i].className = "";
			document.getElementById(linkTarget).style.display = "none";		
		}
	}
	preventDefault(e);
}