Help with Zoom?

Hi - looking for some help with a problem I have with a zooming technique?

I have created a button, which allows an object to be zoomed in on - however I want the object to be restricted so as it will stay within a certain area of the screen for example in a small box and not take over the entire screen when u zoom in?

I have attached the swf file so as you can get a better idea of what Im talking about/

Hope someone has the answer to this?
Thanks

well you’ve got to know the bounds of the amount that you want to zoom and just don’t set the zoomed in amount higher than your bounds… i’m assuming you’re using the Tween class to zoom in so just set the final value to be lower than what you currently have.