function addClass(element, classname) {
    element.className += element.className ? ' ' + classname : classname;
}

function removeClass(element, classname) {
    var removeMe = element.className.match(' ' + classname) ? ' ' + classname : classname;
    element.className = element.className.replace(removeMe, '');
}

function hasClass(element, classname) {
    return new RegExp('\\b' + classname + '\\b').test(element.className);
}

function with_items (klass, func, parent) {
    $A(parent.childNodes).each(function (node) {
        if (node.nodeType == 1) {
	    with_items(klass, func, node);
	    if (hasClass(node, klass)) {
		func(node);
	    }
	}
    });
}