替老美說句話, all the american are 大國沙文主義， never thought the visa problems since they almost need no visa to enter other countries.
Give you a story for my previous professor, he was invited to give a talk in china, he thought it is the same as before. Bought a ticket and directly went to china. Since there is no person check your visa (airline just check your passport, but no visa checkup) before your borading the plane, he didn't have any probelm before landing, once he landed, he was rejected to enter China. He called the chinese invitor, and unveristy sent the vice president to the custom and see whether there is a way to get him to enter China. Oh, even the presiedent, :) no one can let him in. So he just waved his hands byebye from the window glass to the chinese invitor and came back to US from the next flight. :)
So, americans are stupid about visas. not like us, all have the hard experence to get visa :)
