Data Retrival

I have a database with 3 tables in it.(Imagine as there are 3 levels, one level for each table)

on level 1, there are 3 entries:A,B,C

on level 2, the entries are tied to one of the entries in level 1, ie those in level 2 will be A.1, A.2, A.3, B.1,B.2,C.1,C.2.....

on level 3, the entries are tied to one of the entries in level 2, ie those in level 3 will be A.1.1, A.1.2, A.1.3, A.2.1,A.2.2,B.1.2,C.2.1.....

I have 3 combo boxes on my webpage. I want it to be able to do the following:

when i make my choice on combobox 1 which holds the information of level 1, only those entries corresponding to the choice made in combobox1. ie if in combobox 1, i chose A, then i only wan those of A.1,A.2,A.3 to be shown in combobox 2.... after which, say I choose A.1 in combobox 2, I only wan those of A.1.1, A.1.2,A.1.3 to be shown in combobox 3.

Is this achievable in asp and sql since it sort of requires dynamic programming?