There are instructions here for creating dependent data validation lists:

http://www.contextures.com/xlDataVal02.html

jarrowrs wrote:
Having worked out how to create a validation table, I'm now hoping
somebody can tell me that you can change the list displayed depending
on the results of another cell.

Like an IF formula.

--
Debra Dalgleish
Excel FAQ, Tips & Book List
http://www.contextures.com/tiptech.html