menu / sub menu

[NiFkE]

Hi everybody (first time here)

i'm a kinda noobie and i need something, mine doesn't work like i want it.

I have 2 list/menu's in a form. 1 for a Category and one for a Subcategory.
If I select a category in the first list/menu then i must see all the Subcategory's from that category i've selected.

this is what i have: http://www.pastebin.be/2618/

it must look like this:
http://www.kapaza.be/advertise.cfm ( Rubriek: * and SubRubriek: * ).

I hope you understand and can give me a code.

greetings & tnx for reading

[codeexploiter]

I've done something like a tree menu that works on clicking on it earlier. But i've done it using client-side javascript. Check the following thing out, you can write that item client-side script code using server-side code.

http://www.treeview.net/treemenu