Autolookup With Autofilling

Hi there!
It's been almost 10 years since I've done any work with databases, so I'm really REALLY rusty and I barely remember how to do anything. I was wondering if you guys could help me out with a question I have in making a form.
I have 2 tables. The first table has a list of names and ID's. There exist some duplicate names, as some people are associated with more than one ID.
And there are two fields to the ID. One is Called the Client Code, and the other is the Client Division.
So the 1st table, in datasheet view, is basically:

# | Last Name | First Name | Client Code | Client Division

The second table is a list of addresses based on Client Code and Client Division:

# | Client Code | Client Division | Address 1 | Address 2 | Etc

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What I'm trying to do is the following:
I'm trying to create a form such that as I'm typing in a last name, it does autolookup and auto filling. I may have multiple people with the Last name of Smith, so then it dynamically creates a dropdown box with all possible unique first names associated with the last name Smith. And after I choose/type in the first name, I get to two more dynamically created drop-down boxes that list all possible Client Codes and Client Divisions associated with this name. After choosing that, I figure it's a simple autolookup to populate the address fields.
Does anyone have any insight on how I can get this done? Another piece of functionality that I'm trying to work into this is that if the name doesn't exist or if there's a new Client Code and Client Division or a new address, the data gets automatically added to the respective tables.

Does anything of what I wrote make any sense?
Any help would be greatly appreciated.

thanks

Imants