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) {
	if(element) {
		document.removeClass(element, clsName);
		element.className += " " + clsName;
	}
}

document.removeClass = function(element, clsName) {
	if(element) {
		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;
	}
}