What is the kids movie from the late 80s or early 90s were a boy and a girl have a dream or nightmare and they fly around on a bed and go to a mystical world I think the beginning is with real people but in their dream they are cartoons and the a part of the dream world there's a good side and a bad side full of night mares (for some reason I remember a box with cookies and a locked door and the needed to get a key)and rember it being kind of sacry for a little kid