Create a 3 level drop down (select one, then #2, then #3)

Hi, We need a PHP/JS developer to write a 3 level drop down selector. i.e. select country, then city, then street. if #1 or #2 changes, it clears the following. Let us know how to provide the data. if you need it in AJAX, we will provide JSON API. if you need all data in 1 bulk - let us know. We already have the CSS/HTML. the DB is also ready - need a developer to suggest best approach for the pulling. After selection of all 3, a button is in place. once a user clicks it, he will be redirected to our API. that's it. Good luck, Ika, CTO