What would cause the AC to suddenly stop working on a 2004 jetta The fuses look good are there control relays if so where are they?

If the freon is low the AC will not work. I would have it checked for a leak and then refill it. This can be done by getting the proper items needed at a part house of your choosing. If you take it to a dealer check for specials as they will get you for up to 100 dollars that only cost 8 dollars in fuids.