What is the name of a movie that aired on the Disney Channel in the 80's or 90's but probably made in the 70's: it was a combination of live action and cartoon? The main boy in the film had a British accent and he falls into a pond and becomes a cartoon. He has to save a princess named, "Delilah". HELP!!

Could be The Water Babies (1978) (http://imdb.com/title/tt0078477/)

The Phantom tollbooth

The Phantom tollbooth is a book and has nothing to do with that. Could the movie have anything to do with a library? It sounds vaguely familiar... or maybe I dreamed that... uh oh.