I have a baby on the way and would like to turn the top half of her nursery door into a screen. (To allow heating and AC into the nursery--it has no vents--and to keep the cats out). I'm thinking of cutting a hole in the top panel of the door and installing a screen, but I have no idea how to do this -- how does the screen mount to the door? Do they sell custom-sized screen frames to fit into the hole, or do I just nail/staple the screen onto the door (and then attach some kind of trim to cover the sharp edges?) Alternatively, where can I find cheap custom-sized screen door kits, preferably with wood on the bottom 1/3rd or so to prevent climbing/scratching cats? Thanks, chris.