// Event functions from http://www.quirksmode.org/js/eventSimple.html
var addEventSimple = function(el, evt, fn) {
	if (el.addEventListener) {
		el.addEventListener(evt, fn, false);
	} else if (el.attachEvent) {
		el.attachEvent('on' + evt, fn);
	}
};
// alias
var addEvent = addEventSimple;

// Add/remove/has class functions from http://snipplr.com/view/3561/addclass-removeclass-hasclass/
var hasClass = function(ele,cls) {
  return ele.className.match(new RegExp('(\\s|^)' + cls + '(\\s|$)'));
}

var addClass = function(ele,cls) {
  if (!hasClass(ele,cls)) {
    ele.className += " " + cls;
  }
}

var removeClass = function(ele,cls) {
  if (hasClass(ele,cls)) {
    var reg = new RegExp('(\\s|^)'+cls+'(\\s|$)');
    ele.className = ele.className.replace(reg,' ');
  }
}

// getElementsByClass function from ddiaz
var getElementsByClass = function(searchClass,node,tag) {
	var classElements = [];
	if (!node) {
		node = document;
	}
	if (!tag) {
		tag = '*';
	}
	var els = node.getElementsByTagName(tag);
	var elsLen = els.length;
	var pattern = new RegExp("(^|\\s)"+searchClass+"(\\s|$)");
	for (i = 0, j = 0; i < elsLen; i++) {
		if (pattern.test(els[i].className)) {
			classElements[j] = els[i];
			j++;
		}
	}
	return classElements;
};