adding/removing items manually from 2 level interdependent lists

[Edokun4]

I found similar topics and some are similar but not exactly to what I want to do.

From a 2 level interdependent select list, I want the user to be able to add/modify/remove items.

Something similar to what is in here;

http://www.javascriptkit.com/javatut...content2.shtml

Any help will be greatly appreciated!