Hi - I plan to be in Chiang Mai this coming fall, traveling on a U.S. passport. I understand I can get initial 30 day stay without visa / visa exempt I believe is the term. Can I then extend this for another 30 days? If so - what is cost and where can it be done - in Chiang Mai? Finally, what type of documents, tickets, etc are needed 1) on arrival and 2) when applying for extension. I will have a departure airline ticket to exit / return to the U.S. before having been in Thailand for a total of 60 days. My thanks in advance.