Bought one of those "As Seen On TV" screen doors with the magnets at Family Dollar for $15 on Friday. Have a slight problem with it. The length was a tad too long. My door opening is 79" high and the screen is 82-1/2" (says 83"). But that's not the problem. The magnets are attracted to the steel door and the steel entry steps!
Otherwise it works okay. I do need to get a long roll of velco to attach it to the door framework rather than the short strips. When I do that (this winter when the bugs are less thick), I will shorten the screen door by putting a hem in it with a few weights (even a light breeze blows it inward then the bottom magnets stick to the steel step risers) and tailor it to fit better. The magnets REALLY like the steel door.