Cat Friendly Interior Door

Problem:
  You need a cat to always have access to a room, so the door should be left open, but  the door should also be able to be closed if you want to.

Solution:
   It was so easy, that I actually hesitated to make an Instructable.

Step 1: What You Need and How to Do It.

Materials:
  2 nails
  1 rubber band.

Tools:
  Hammer.

How-to:
 Fasten the two nails in the upper corner of the door post and connect a rubber band between them. The door will now always stay partly open.