I am traveling from Budapest to Split in July. I have researched the schedule for that time frame and have found that there is a night train that goes through Zagreb without having to change trains and they run on Tuesdays and Fridays. Here is my problem, I go to the website and I cannot figure out how to book the reservation. I am continually advised that no offer is available no matter what Tuesday or Friday I use in June, July or August. Is it possible that the train is sold out? I can book to Zagreb, but cannot book from Zagreb to Split. So very confused. Anyone have any ideas?