Elastic sizing not scaling

[FONT=Verdana][SIZE=2][COLOR=black][COLOR=black][FONT=Arial]Hi[/FONT][/COLOR][/COLOR][/SIZE][/FONT]

[FONT=Verdana][SIZE=2][COLOR=black][COLOR=black][FONT=Arial]i am working on movie clip that will change dimensions ( width and height ) depending on the loaded picture size .[/FONT][/COLOR][/COLOR][/SIZE][/FONT]

[FONT=Verdana][SIZE=2][COLOR=black][COLOR=black][FONT=Arial]I made an easing transformation and works fine.[/FONT][/COLOR][/COLOR][/SIZE][/FONT]

on (release) {
this.onEnterFrame = function() {
_root.box._width = _root.box._width+(200-_root.box._width)/2;
_root.box._height = _root.box._height+(250-_root.box._height)/2;
};
}

[FONT=Verdana][SIZE=2][COLOR=black][COLOR=black][FONT=Arial]I think that it will be much more flashy if I make this transformation bouncy or elastic [/FONT][/COLOR][/COLOR][/SIZE][/FONT]
[FONT=Verdana][SIZE=2][COLOR=black][COLOR=black][FONT=Arial]I started by searching for tutorials but most of them were about elastic scaling (the shape is changing as one peace )[/FONT][/COLOR][/COLOR][/SIZE][/FONT]

[FONT=Verdana][SIZE=2][COLOR=black][COLOR=black][FONT=Arial]But nothing about sizing , I mean putting a specific value for width and height .[/FONT][/COLOR][/COLOR][/SIZE][/FONT]

[FONT=Verdana][SIZE=2][COLOR=black][COLOR=black][FONT=Arial]I hope that you can give me any good point to start from .[/FONT][/COLOR][/COLOR][/SIZE][/FONT]

[FONT=Verdana][SIZE=2][COLOR=black][COLOR=black][FONT=Arial]Thanks [/FONT][/COLOR][/COLOR][/SIZE][/FONT]