EXACTALLY the same question was asked a few strings below. Search before you
post.
ANSWER:
http://www.contextures.com/xlDataVal02.html


"Oct1196" wrote:

I need to crease a dependent list where the use can select multiple options
to the validation selection. for example, my list contains each state, the
dependent list contains the counties for each state. I need to lelect, All
counties, One county or individualy select as many as applies.