The Big Kahuna

On the last evening of a convention two seen-it-all industrial lubricant salesmen and a youngster from the research department gather in the hotel's hospitality suite to host a delegates party. The main aim is to get the business of one particular big fish. When it becomes apparent that it is the lad who has developed a direct line to the guy, his strong religious beliefs bring him into sharp conflict with his older and more cynical colleagues.

The Big Kahuna is a 1999 movie adapted from a play entitled Hospitality Suite, written by Roger Rueff, who also wrote the screenplay. John Swanbeck, the director, makes few attempts to lessen this film's resemblance to a stage performance: the majority of the movie takes place in a single hotel room, and nearly every single line of dialogue is spoken by one of the three actors.

Source: Wikipedia