Module development and code questions

i am trying to write my own module. i didnt like the way taxonomy lists categories so i added 2 selectboxes and update the child with XAJAX. everything works fine. but if i submit the form i got an error saying :

An illegal choice has been detected. Please contact the site administrator.

Sorry I can't find this kind discuss and info in Handbook,
so i want to ask,
If drupal support C/C++ extension or API,
let developer can write modules with C/C++ ??

Thanks

I am trying to work on the little known directory module and I want to take a tree object that comes from $tree = taxonomy_get_tree($vid); and turn it into a menu uls and sub-ul's like drupal does with it's menu system. I feel like that gives me the most flexibility from a layout perspective. So I would have ul, li, li, li then if theres a submenu I'd have a ul inside one of the li. Anyways it's probably like one function call or something. Thanks

Jay

Hi
I'm getting a bit confused here.
I have gallery2 embedded in Drupal and all is working well. What I want is to get rid off any html being used input formats . At the moment it is limited to filtered html, but I'd rather bbcode. I know that gallery2 people have contributed to a drupal bbcode_wysiwyg module , but ...
Where do I get this module ; or where do I go to see its development ?
Thanks
kate

I have a number of sites running off the same Drupal installation (multi-site). I just installed a new module and would like to enable it for all sites.

Is there a method for doing this without going to each sites 'admin/modules page' and manually clicking the checkbox and submitting the form?

I am looking for a way to make certain users of my social networking site to set their profile to private, so only their friends can access the content. I have looked at a few modules and posts, but I am not finding what I want. Is there a way to add a buddy list (I use the buddylist module right now), and only those on the buddy list can see the blog in question, while all other blogs default to public? Kind of how Facebook allows you to make it so only your friends can view your profile, or those in your network, or everyone, or how private, underage myspace accounts work.