Documentation : Available Methods ( Free Service )
Method - getcountries
This should be the first method called and it will return all of the countries and their abbreviations that the API knows of. Taking the abbreviation and sending it to the getregions method will return all the states/provinces in the country.
Method - getregions
This method will return all of the states/provinces/regions within a selected country. The input must be a valid abbreviation (abbr) from the method getcountries.