document.getElementsByClassName = function(clsName) {
	var retVal = new Array();
	var elements = document.getElementsByTagName("*");
	for(var i = 0; i < elements.length; i++){
		if(elements[i].className.indexOf(" ") >= 0) {
			var classes = elements[i].className.split(" ");
			for(var j = 0; j < classes.length; j++){
				if(classes[j] == clsName)
					retVal.push(elements[i]);
			}
		}
		else if(elements[i].className == clsName)
			retVal.push(elements[i]);
	}
	return retVal;
}

document.addClass = function(element, clsName) {
	element.className += " " + clsName;
}

document.removeClass = function(element, clsName) {
	var $classes = element.className.split(" ");
	for(var $i = 0; $i < $classes.length; $i ++) {
		if($classes[$i] == clsName) {
			$classes.splice($i, 1);
			break;
		}
	}
	$classes = $classes.join(" ");
	element.className = $classes;
}