More explicit HTTP status codes counting as "success"

While "199 < code && code < 300" is technically equivalent to "200 <= code && code <= 299" when code is an integer, the latter is more explicit/readable/understandable.

If it's all about saving JavaScript characters, I'd suggest creating some local variables for commonly used values (such as Request.status) _before_ resorting to micro-optimizations like this one.