CodeIgniter using MySQL

[eluser]MaxEisley[/eluser]
Hello,
i have this answer, i have 2 tables, address and customer, down you can see structure:

address table
------------
addressID PK (AutoInc)
Town
Street
ZIP

customer table
------------
customerID (AutoInc)
Name
addressID FK

Ok, i will work with these 2 tables. There is a form where you can fill customer Name and address. After filling form i want to add information to 2 tables, but i am not sure how FK works.

Firstly add address info to address table, addressID will be generated with autoincrement.
Then get actualy addressID and add customer info to customer table.

How can i get actually addressID ? Is there some fast way ?

Thanks for help.