// JavaScript Document

window.onload = assign;

function assign() {
	var menu = document.getElementById('menu');
	var choices = menu.getElementsByTagName('li');
	var num_choices = choices.length;
	for (var i=0; i<num_choices; i++) {
		var sub = choices[i].getElementsByTagName('ul');
		if (sub.length > 0) {
			addEvent(choices[i],'mouseover',showSub);
			addEvent(choices[i],'mouseout',hideSub);
		}
	}
}

function showSub(e) {
	var sub = this.getElementsByTagName('ul');
	sub[0].className = 'sub';
}

function hideSub(e) {
	var sub = this.getElementsByTagName('ul');
	sub[0].className = 'sub hidden';
}





/*http://onlinetools.org/articles/unobtrusivejavascript/chapter4.html*/
function addEvent(obj, evType, fn, useCapture){
  if (obj.addEventListener){
    obj.addEventListener(evType, fn, useCapture);
    return true;
  } else if (obj.attachEvent){
    var r = obj.attachEvent("on"+evType, fn);
    return r;
  } else {
    alert("Handler could not be attached");
  }
}