Here is an excerpt from a major US University for the information of foreign students with entry visas. I suspect it is a good start for the member of yor group with a Thai passport:
Travel Abroad
For specific guidelines for checking whether all of your documents are in order for travel, please review our Visa Documents Guidelines table.
Before entering your home country, you will need a valid passport, or some other acceptable proof that you are a citizen or legal resident of that country and have the right to return to and enter it.
Before entering another country, you should contact the country's consulate or embassy and obtain a visa, if one is required for citizens from your country of citizenship or lawful residence. One of the basic rights of any country under international law is the right to determine who may enter its borders, under what conditions and rules they may enter, and how long they may stay...
Contact the embassy or consulate of the country you plan to visit before you leave the U.S. in order to save yourself much time, trouble, expense, and disappointment at the border or airport. To obtain contact information for the embassy or consulate of the country you plan to visit, check the Washington D.C. Embassies list(link is external) or call directory information in Washington, DC at 202-555-1212 and ask for the telephone number of the embassy of the country.