I need to create a log in page for new customers, where in they provide their address in the US based on the zipcode. Essentially, if a user fills in a zip code, it should automatically populate the city and state.

For some situations, I also want to create a customised table of addresses like if a user gives its company's name then I want to provide 'valid' additional list of values for the company's floor and cube numbers.

Any guidance on writing this code or ready made available code for this would be welcome.

Thanks