MovieClip "workspace" help! Need more space to ad things!

I have a weird question, maybe silly.

I am using the scrollpane component, and linking a movieclip with it. Well its a movie clip full of buttons that load swfs. The are all in a line going vertically down. ( hense the scrollpane )

When I am working on the movie clip ( adding buttons to it ) the “workspace” ends. So now I can’t get it to get bigger so I can keep adding buttons.
Its very narrow and long list of buttons.

My question is; is there a set limit to the working space size on a MC, if not, how do I make it bigger so I can add more buttons to the MC?

THANKS SO MUCH, i am kind of at a stand still now. ANY HELP WOULD BE GREATLY APPRICIATED!!