Hierarchy for properties in forms

[PDavide]

Dear all, I am using properties for attributing thematic categories to
pages and I have one question for you.
The categories I have to use are already organized in their own 3
levels hierarchy, like:

topic 1
- subtopic 1a
-- sub-subtopic 1a1
-- sub-subtopic 1a2
- subtopic 1b
-- sub-subtopic 1b1
-- sub-subtopic 1b2
- subtopic 1c
-- sub-subtopic 1c1
-- sub-subtopic 1c2
topic 2
- subtopic 2a
-- sub-subtopic 2a1
etc...

I'd like users to be able to follow a topic's pattern before
attributing a value, like:

1 - see all topics (first level) > choose topic
2 - once they've chosen the topic, they can the list of eventual
subtopics (second level) related to the topic you've chosen > choose
subtopic
3 - and so on for further levels in the taxonomy

Header Tabs constitute a partial solution, since they cover only one
level: first level topics in header tabs, second level topics listed
under each tab. But what if you need to include a third level?

For now, I am using the complicated method you may see here:
http://undp-crs.referata.com/wiki/Special:AddData/MPN_Query/Ttt

Example:

topic = HR > dedicated tab (thanks to Header Tabs)
sub-topic = Duties and Obligations > title of a paragraph
sub-sub-topic = Awards > listbox

Is there any way to make this process simpler and clearer? Any Ajax
like solution compatible with Forms and SMW? Any generally brilliant
idea?

Thank you very much,

Davide

[Yaron Koren]

Unfortunately, I don't believe there's any way to do that; certainly not with Javascript. Although the interface you came up with is pretty ingenious, I'd say.

-Yaron