Help with trigonometry and flash?

Hi all.

I am currently trying to create a small zoom function by loading images and text into a small, randomly-rotated clip inside a larger container clip. When the smaller clip is clicked, it rotates and scales the larger container clip and effectively the smaller image is rotated to be right side up and zoomed to 100%.

So far this is moderately successful. I can scale and rotate the larger clip fine, but I want the smaller image to be centered on the screen, and so far I’ve been unsuccessful.

I’ve been building this in AS2 OOP, and I’ve attached a small .zip with the working version.

Can anyone help me center the image?