There's a bug in the removeClass() function. If you use a class with a reserved regex character it will fail. I'd rather see this done with a small sets librar

There's a bug in the removeClass() function. If you use a class with a reserved regex character it will fail. I'd rather see this done with a small sets library anyway. removeClass = function (el, cl) { el.className = _.without(el.className.split(' '), cl).join(' '); }