Let the students and teachers know that you have stepped out of your office with this "The principal is....in/out" sign. The border is black and white polka dot with a brown owl holding a bright red apple. Laminate the sign and the In/Out signs. Place a small piece of Velcro on the sign and on the in/out signs and then you are able to change it as needed.
(owl clip art provided by www.mycutegraphics.com)