[horde] Horde methods for conditionally populationg drop-down menus?

[Kevin M. Myer]

I'd like to populate one drop-down menu on a form, based on the selection value
of another.  Are there existing Horde Form functions that will simplify this
process, in terms of generating what I assume would be the necessary Javascript
to make this happen?

Specifically, I'm looking at having the Category field in Kronolith's new event
screen be populated with values that match those of the share owner's.  So that
if a user chooses a share to add an event to that is not their own, they would
be presented with the share owner's categories, and not their own.  But for me,
at least, this wouldn't be Kronolith specific, but apply to any share.

So what I'm thinking, in theory at least, is that for each share, lookup the
owner's categories,  Build an array with the key being the owner, and the value
being the category.  Use Javascript (?) to toggle between the sets of arrays,
based on what share  is chosen.  I'm looking for an easier way to do that,
instead of writing all the Javascript and form code from scratch (although
admittedly, not being a developer, there may be a far simpler way to do this). 
Would Horde_Form_Action_updatefield be a proper Class to use?

Kevin

-- 
Kevin M. Myer
Senior Systems Administrator
Lancaster-Lebanon Intermediate Unit 13  http://www.iu13.org