Need some help with a query - categories/sub-categories - Joomla! Forum - community, help and support

hello joomlers,

i'm making component , need output select list out of categories table. i've seen com_users uses functions acl class.

i have following table:

catid
name
parent

the catid auto_increment value, name category , parent home category of it. if parent 0 category root category, if parent value category name of parent value , category sub-category.
i need know how display select option sub-categories

example:

catid:1 name:audio parent:0
catid:2 name:video parent:0

catid:3 name:mp3 parent:1
catid:4 name:wav parent:1

catid:5 name:avi parent:2
catid:6 name:mov parent:2

and html select like:

audio
- mp3
- wav
video
- avi
- mov

does sheds light on me since i'm completly lost here? i've tried lot of stuff results failed.

thanks in advance