I just had to let a bird, not Magpie but Sparrow, out of my house. This is the second time i've had a bird in my house this year. Older style house with storm type windows, no screens, but no direct flight in either. Watching them trying to fly through a window is confirmation that they super stupid.
For getting rid of Magpies... listed are some humane ways that might work.
http://www.thriftyfun.com/tf596053.tip.html