The Private Eyes

I love this film. It has a kind of comedy and fun that the whole family can watch, and other then one small part that might scare only the extremely young it is a good little mystery. The key to enjoying films like this is to just love it for the screwball, zaniness. Then there is the also a special feature of Tim Conway doing commentary with the producer of the film, well worth hearing if you have the time.

http://www.imdb.com/title/tt0081376/