Duplicate movieclip help plz!

Im trying to make it to where I click a button and it takes a movie clip from my libraire and places in the center.
I have tried using the duplicate movieclip function but it won’t work right.
how do I do this?

If you’re fetching something from the library, shouldn’t you be using attachMovie?

I don’t know let me try

… later

it won’t work here is my AS

on (press){
	attachMovie (doorc)

doorc is a movieclip from my library but it won’t work

There is a pretty good description of how to use attachMovie after the 3rd block of code on this page: http://www.kirupa.com/developer/flash8/animateDynamicMC4.htm