Adding Thumbnails Gallery Help!

Morning all,

I’m trying to edit the ‘Adding Thumbnails’ gallery
(http://www.kirupa.com/developer/mx2004/thumbnails.htm)

What I’m wanting to do is make the thumbs go from top to bottom rather than from side to side. Is this possible and if so can anybody tell me how? I’m not the most experienced actionscripter. Basically I want the main picture on the left and the thumbs scrolling down the right hand side.
Also if it is possible can I use a hotspot like a picture of an arrow to show where the user has to hover for it to scroll? This is less important at the current time though.

Thanks,
Jon