Resizing Buttons in Tandem?

If anyone knows a slick way to pull this off, I would be most grateful if you explained it to me.

A simple example; There are four Rectangle Buttons sitting close together on the Stage. When I Rollover any one of them, it expands to become a square. When it does, the rest of the rectangles instantly change their size to make room for the square.

I know I could do this with tweens, but I’m wondering if there is a way to do this in Action Script.

Thanks a ton.

JD