Event Handlers & Validation Lists

[Simon]

Hi,

In Sheet 1, Cell A1 I have a validation list which contains a list of
customers, cell B1 needs to be a validation list that holds the products
which the customers have purchased to date.
Sheet 2 contains a list of all customers which is where the data validation
list on Sheet 1, Cell A1 is sourced from.
Sheet 3 contains a list of all the products that each customer has
purchased, this needs to be the source data for the validation list on Sheet
1, cell B1.

I need to be able to do the following:
Once the user selects the customer from the validation list in Cell A1 a
macro needs to fire that updates the list of products in B2 that the
particular customer has purchased. The list of products purchased by each
customer are on Sheet 3. I was thinking of grabbing the client name in A1
and using that to perform an auto filter on the customer product listing on
sheet 3 and then somehow copying the products from the auto filter and using
that as the basis as the validation list for B2. Only problem is that I have
no idea how to do this?

your help would be greatly appreciated.

Thanks.
Simon