disconnected dataset

hello,

i have table1(id1 PK) and table2 (id2 PK, id1 FK). i populate a dataset with table1 - bound to listbox1, and table2 (which i want to bind on listbox2).

when selecting an item in listbox1 (for which id1 = value) i want to display in listbox2 only the items from table2 that have id1 = value.

how do i do this using a datadapter?

[i only know how to perform this task working directly on the database, not on the dataset].

thanks