Code:
import mx.transitions.Tween;
import mx.transitions.easing.*;
stop();
// set stage scaling
Stage.scaleMode = "noScale";
Stage.align = "TL";
// tween variables
var tweenX1, tweenX2;
var tweenY1, tweenY1;
mcBotLeft.pinX = mcBotLeft._x;
mcBotLeft.pinY = Stage.height - mcBotLeft._y;
mcBotRight.pinX = Stage.width - mcBotRight._x;
mcBotRight.pinY = Stage.height - mcBotRight._y;
// resize event
Stage.addListener(this);
function onResize() {
	// stop any tweens if playing
	tweenX1.stop();
	tweenY1.stop();
	tweenX2.stop();
	tweenY2.stop();
	tweenX1 = new Tween(mcBotLeft, "_x", Bounce.easeOut, mcBotLeft._x, mcBotLeft.pinX + 30, 0.5, true);
	tweenY1 = new Tween(mcBotLeft, "_y", Bounce.easeOut, mcBotLeft._y, Stage.height - mcBotLeft.pinY - 30, 0.5, true);
	tweenX1.onMotionFinished = function() {
		tweenX1.continueTo(mcBotLeft.pinX, 0.5);
	};
	tweenY1.onMotionFinished = function() {
		tweenY1.continueTo(Stage.height - mcBotLeft.pinY, 0.5);
	};
	tweenX2 = new Tween(mcBotRight, "_x", Bounce.easeOut, mcBotRight._x, Stage.width - mcBotRight.pinX - 30, 0.5, true);
	tweenY2 = new Tween(mcBotRight, "_y", Bounce.easeOut, mcBotRight._y, Stage.height - mcBotRight.pinY - 30, 0.5, true);
	tweenX2.onMotionFinished = function() {
		tweenX2.continueTo(Stage.width - mcBotRight.pinX, 0.5);
	};
	tweenY2.onMotionFinished = function() {
		tweenY2.continueTo(Stage.height - mcBotRight.pinY, 0.5);
	};
}
// immediately fit to current size
onResize();