ActionScript 2.0 :: Photo Gallery - Big Display / Fade Effect

I am new in the marvelous world of flash 8. I am building now my photo galley that I will then include in my Web site. Here are my 2 questions : My pics are featured in a big display with a thumb gallery under it. Until now I managed to create a mouse rollover effect on the thumbnails so that a big image of the thumbnail appear in the big display when I roll my mouse over its thumb. Codes are ok everything work perfectly. I want now to create 2 things :

1 : I want my images to appear in the big display by fading and
2 : I want a bigger preview window of my thumb when I roll over my mouse on each of them ( the preview window appear more or less like a tooltip and strech)

Here is the code I basically use for the gallery I achieved till now.
btn1_btn.onRollOver= function(){
myScreen_mc.gotoAndStop(1); };
btn1_btn.onPress = function() {
getURL("04big.jpg"); };
btn2_btn.onRollOver= function(){
myScreen_mc.gotoAndStop(2);
} btn2_btn.onPress = function() {
getURL("06big.jpg"); };