If you don't have a specific state field that's going to be very difficult or inaccurate. If state is in cb_address you will likely need to use an Advanced filter to cover the different variations someone would specify state. Example as follows.
Code:
( `cb_address` LIKE '%Georgia%' or `cb_address` LIKE '%GA%' )
The problem with that is if you just match GA you could match parts of addresses so you'd really need some sort of formatting for the address to enforce. The best approach is to have a select field with the states all predefined in it then there's no guesswork as you'd just filter to the values you've specified for the states.
krileon
