The DOOR is OPEN on JK's site!!!!!
Go via the hairband portkey to the room with the door and click on the handle. The door opens and you'll see a BLACK SPACE...
If you want to solve the puzzle yourself.... got for it. :~) Or if you're impatient like me, check out TLC. You'll find the key in the comments.
Talk about excting!!!! :~D :~D :~D