The audience is wrong individually and always right collectively. If they don't laugh, it isn't funny. If they cough, it isn't interesting. If they walk out, you are in trouble.
A book is a concept and a structure, and dialogue is the smallest part. You can have the best score in the world, but if the book is weak, it won't work. On the other hand, if the book is good, it can carry a mediocre score.
[accepting his Oscar for "Father Goose"]: I'd like to thank Cary Grant, who keeps winning these things for other people.