Scaling Question

I have a navigation. Basically it is 4 boxes that are stacked vertically. When I roll over a box it scales to 150%. What I want to do is keep the spacing between the boxes constant so that the scaled box does not overlap the other boxes. So when one box scales up the others slide up or down to maintain constant spacing between each box.

Can someone help me with the code? I am not sure how to begin to script this?