Looking for help to create Cascading & dynamic checkboxes

[Frank]

Hello Champs

Is there a way to create Checkbox groups from a secondary source that meets
the following criteria? (sample follows, sorry, I have no idea to describe
that any better)

1) "Level1" is shown by default (i.e Checkbox Group "Headline"
2) If one or more "Level1" Checkbox is flagged by the user, the
corresponding sub entries should appear and allow defining the choice even
more explicit. One or more Checkbox may be flagged, even all.

Samples for a "Level1" (using products to make it more easy):
-> Server Operating System
-> Desktop Operating System

Samples for the corresponding "Level2" when "Level1" is flagged:
->Server Operating System
--> Windows Server 2003
--> Windows 2000 Advanced Server

Samples for the corresponding "Level3" when "Level1" AND one or more
"Level2" option has been flagged:

-->Server Operating System
--> Windows Server 2003
--> RTM
--> SP1
--> SP2
--> Windows 2000 Advanced Server
--> RTM
--> SP1
--> SP2
--> SP3
--> SP99

I am currently using the follwing xml to feed cascading dropdown, but I dont
like that option too much... therefore I would love to use checkboxes and
even being able to set default values for the most common choices.

<?xml version="1.0" encoding="UTF-8"?>
<productlist>
<productcategory value="Server OS">
<productfamily value="Windows Server">
<productversion value="Windows 2000 Standard Server">
<servicepacklevel value="RTM"></servicepacklevel>
<servicepacklevel value="SP1"></servicepacklevel>
<servicepacklevel value="SP2"></servicepacklevel>
<servicepacklevel value="SP3"></servicepacklevel>
<servicepacklevel value="SP4"></servicepacklevel>
</productversion>
<productversion value="Windows 2000 Advanced Server">
<servicepacklevel value="RTM"></servicepacklevel>
<servicepacklevel value="SP1"></servicepacklevel>
<servicepacklevel value="SP2"></servicepacklevel>
<servicepacklevel value="SP3"></servicepacklevel>
<servicepacklevel value="SP4"></servicepacklevel>
</productversion>
<productversion value="Windows Server 2003">
<servicepacklevel value="RTM"></servicepacklevel>
<servicepacklevel value="SP1"></servicepacklevel>
<servicepacklevel value="SP2"></servicepacklevel>
<servicepacklevel value="SP3"></servicepacklevel>
<servicepacklevel value="SP4"></servicepacklevel>
</productversion>
<productversion value="Windows Server 2003 R2">
<servicepacklevel value="RTM"></servicepacklevel>
<servicepacklevel value="SP1"></servicepacklevel>
<servicepacklevel value="SP2"></servicepacklevel>
<servicepacklevel value="SP3"></servicepacklevel>
<servicepacklevel value="SP4"></servicepacklevel>
</servicepacklevel>
</productversion>
</productfamily>
</productcategory>
<productcategory value="Desktop OS">
<productfamily value="Windows">
<productversion value="Windows XP">
<servicepacklevel value="RTM"></servicepacklevel>
<servicepacklevel value="SP1"></servicepacklevel>
<servicepacklevel value="SP2"></servicepacklevel>
<servicepacklevel value="SP3"></servicepacklevel>
<servicepacklevel value="SP4"></servicepacklevel>
</productversion>
<productversion value="Windows VISTA">
<servicepacklevel value="RTM"></servicepacklevel>
<servicepacklevel value="SP1"></servicepacklevel>
<servicepacklevel value="SP2"></servicepacklevel>
<servicepacklevel value="SP3"></servicepacklevel>
<servicepacklevel value="SP4"></servicepacklevel>
</productversion>
<productversion value="Windows 2000">
<servicepacklevel value="RTM"></servicepacklevel>
<servicepacklevel value="SP1"></servicepacklevel>
<servicepacklevel value="SP2"></servicepacklevel>
<servicepacklevel value="SP3"></servicepacklevel>
<servicepacklevel value="SP4"></servicepacklevel>
</productversion>
<productversion value="Windows Slapstick">
<servicepacklevel value="RTM"></servicepacklevel>
<servicepacklevel value="SP1"></servicepacklevel>
<servicepacklevel value="SP2"></servicepacklevel>
<servicepacklevel value="SP3"></servicepacklevel>
<servicepacklevel value="SP4"></servicepacklevel>
</servicepacklevel>
</productversion>
</productfamily>
</productcategory>
</productlist>

ANYONE patient enough to help?
I guess this isn't really easy