Need to create dropdowns in Excel

[Guest]

Hey,

I have a list of clients in Cells A1..A3. This list is ever changing and may
go from three to thirty clients!

Cells D1..E12 contain an ever-changing list of projects per client (Client
Names in column D and Project Names in column E), thusly:

Column D Column E
-------------------------------
Client-1 Project-1
Client-1 Project-2
Client-2 Project-3
Client-2 Project-4
Client-3 Project-5


What I'd like to do is:
A) display a dropdown-list of clients in Cell AA1 and then,
B) display a dropdown-list of corresponding projects in Cell AB1 depending
on the client selected in AA1.

For A) I understand I can use Data-->Validation and point it to a list
For B) How do I program the dropdown to be dependent on what was selected?
Is this something that can be done..programmatically or with a macro (note
the list of clients and projects keep changing...almost on a bi-weekly basis).

TIA,

FxAS

 

[Debra Dalgleish]

There are instructions here for creating dependent data validation lists
from a sorted master list:

http://www.contextures.com/xlDataVal13.html