newbie query question

[B Tuttle]

Hi-
We are trying to set up our first mapserver app. We have two polygon
features one is an index and the other is counties. What we'd like to
do is  be able to type in a county name and get back all the polygons
from the index feature that are intersected by that county (so if even
a portion of the index polygon is in the county it would be returned
as a result). The index polygon feature does not have county names in
it so we are hoping to do this without trying to add county names to
the index feature (especially since an index polygon can be in more
than one county).