The treaty allows for American citizens and businesses incorporated in the US, or in Thailand to maintain a majority shareholding or to wholly own a company in Thailand, and thereby engage in business on the same basis as would a Thai national.
at airport you get it when you go thru departure area of immigration, its 1,000 baht and does NOT stop you visa when ur gone so if ujr visa ends May 1st even with a re entry permit it ends May 1st
better come back in and receive a visa exempt entry