Perspective Footer Size

How can I control the size of a footer in perspective. I would like it to be about 50 px high but it is always about 200 px high no matter what settings I change. When I used to do web development I remember that the footer size was always a pain to fix. Any suggestions on how to customize the size of the footer so that no matter what screen size I use the footer is always 20 px in height.

In the Docked View configuration area of the Page Configuration panel, you want to set the Size property.