Titular tripe, with a laugh or two between the lumbering, limping lameness.
The lack of restraint and near nonexistent teasing undermines most of the [rim]shots at humor.
You have to build up jokes, not simply squirt them in people's faces at random.
Comic actors general help a comedy, too.
Waiting 44 minutes before bringing in a pro for a cameo exposes the myopia of the film-makers.
Hint: if you can;t think of any good comic situations or one-liners, steal some from the classics... Aristophanes, Twain, Chaplin, The Stooges, ~Zeppo Marx, even.