ActionScript 2.0 :: Fullscreen Flash Layout - Fade In Browser Background?

I want to fade in the full browser background, however most of these tutorials I have seen have it loaded somehow with the BitmapData or another class, and when it is done this way, I cannot add any animation. Others, the background covers the whole browser, but it doesn't really resize, so most of it is just cropped out. Some, the positioning isn't always consistent for all resolutions. Some don't really explain how to position images in different parts of the Flash besides the direct center, top left, top right, etc. They will tell you how to get these spots, but not other spots.

Code:
import flash.display.BitmapData;
cover._x = Stage.width/2;
cover._y = Stage.height/2;
rock._x = Stage.width/2+265;
rock._y = Stage.height/2;
var tile:BitmapData = BitmapData.loadBitmap("tile");
function fillBG() {
[Code] .....

The reason I chose to stick with this one is that is the positioning is perfect. Positioning looks the exact same in all resolutions and what not, so this is what I want. But as you can see, it uses a BitmapData class, so I don't know how to add any animation because the file isn't even on the stage. It's in the library and I get this effect by giving it an identifier. Also, the background doesn't resize. It fits the whole browser, but most of it is cropped about like I mentioned earlier. The video tutorial really didn't cover the best way to adjust size, so now that I have the perfect way to position my clips, I don't know how to resize them, so they still look good. I remember in another tutorial I was guessing random numbers such as:
example._height = Stage.height / 2.58430953;

I basically just plugged in random numbers until it looked closest to the way I wanted it to. The problem with this was that image quality was reduced.

The Background
- Must be able to add animation to the full browser background
- Background must be resized so that nothing is missing from the original image, not cropping to fill the whole browser, resizing to fill the whole browser.

Positioning (Not really a problem now but...)
- An easy way to position anything where ever you want.
- Consistent in all resolutions.

Scaling Clips
- A way to scale clips so they just fine in all resolutions so that an image with a width of 512 px that looks great in 1280x1024 doesn't end up taking half of someone screen's that uses a 1024 x 768 resolution.
- No loss of quality.