Module development and code questions

Hello,

Is anybody know how create dynamic select.
I have my own module and 2 select.

For example:
Select №1: array (BMW AUDI Mersedes...)
Select №2: array (520, 525, 530, 80, 100, 120, E200, E210, E220...)

How could i get in 2 select "520", "525", "530" if I chouse "BMW" in 1 select ?

Has anyone yet created a module that automatically inserts adsense/other code inside a node, without actually having to edit the node? I've searched both on drupal.org and outside but have not found anything.

Turns out that it wasn't too hard to implement, I am very impressed at the clean modularity of the Drupal system. I just learned how to do modules today.

Here's my first crack at it. Is this reinventing the wheel? If not, should I check this in to the modules repository?

I am using 4.7 with access control, category permissions, and tagadelic.

Even if I access control content type by category permissions, it seems the same rule can not　be applied tagadelic (tagging cosmo).
Hence tagging cosmo ("tags in xxxx") appears to those who can not get access to that content type.
Appreciate if someone could offer some advice.

Regards,

I used form APIs to create a form page and after I clicked 'submit', I want still go to the same page and send the form values to this page so I can use $_POST['xxx'] to get it. How to do it? In the _submit function I do not know how to write...

I've recently been using nodeapi in my PayPal module to restrict access to parts of an advert before it is paid for. This was ideal for me as nodeapi can effect any kind of node type I was able to allow admins to choose which types should be paid for, including CCK created types.

This led me to wonder: Would it be possible to extend nodeapi to allow it to secure a site? Not just modify the node at various key stages as it currently does but allow it to completely prevent access to a node.