V3 Gallery by Scotty

I’m trying to build up a photo gallery based in the V3 gallery made by Scotty. I’m almost done with the gallery and it’s working fine, i just need to add 2 more things to the gallery but not results yet. First i would like to know if it’s possible to add a “close or back” button to the main picture, so each time the user click on a thumbnail and the main picture is loaded the user can press this button and close it. My idea is to open the main picture over the thumbnails, then after the user take a look of the current picture, he could close it by pressing this “close or back button” and then go back to the thumbnails to choose another pic (hope it makes sense).
The second thing i would like to do is to add a roll over effect to the thumbnails, something like on roll over modify the alpha, or add to each of the thumbnail a sound . i been trying this but i can’t figure out how to modify the AS to achieve it.
Maybe i’m asking for too much, but if anybody can help, it’ll be really appreciated.
Thanks!