Category & Sub-Cateogry ordering

[Igloo]

Well, I have a MySQL Database with the following structure:

category
--------------
id |  name  | description  | orderby
------------------------------------
1  | first  | first ones   |   1
2  | second | second ones  |   2


subcategory
--------------
id |  name  | description | orderby | parent
--------------------------------------------
1  | games  | All games   |   1     |   -1
2  | movies | All movies  |   1     |   1
3  | people | All people  |   1     |   2
4  | music  | All music   |   2     |   2 

Basically, from that information I need a function that can do something like this with output in HTML:

---------------------------------------------
|Games (Lone category/subcategory)          |
---------------------------------------------
|First (Category)                           |
---------------------------------------------
|Movies (Subcategory of First)              |
---------------------------------------------
|Second (Category)                          |
---------------------------------------------
|People (Subcategory of Second)             |
---------------------------------------------
|Music (Subcategory of Second)              |
--------------------------------------------- 

Basically, the orderby column in both tables (category, subcateogry) dictates in which order they will go in; 1,2,3 etc.

The parent column in the subcategory table is the id number of a category, in which subcategories would go into. If this value of parent equals "-1" then it has no category and is in fact a lone subcategory/category, that will display normally ordered by the orderby function.

It is sort of like the way a vBulletin and other forum software works in displaying forums and categories.

Any help is appreicated,
Thanks.

[jofa]

Why two tables?
(When one is all you need: http://www.sitepointforums.com/showt...970#post642970)

Sql examples, tree structures:
http://www.sitepointforums.com/showt...threadid=86795