1 lg. box graham crackers
2 lg. pkgs. instant vanilla pudding
1 can chocolate icing

Prepare pudding according to package directions. Set aside. Place whole crackers on bottom and sides of 9 x 13 x 2 inch pan, (breaking crackers if necessary to fit pan). Top with a portion of pudding mixture. Continue layering alternately, crackers and pudding, ending with crackers on top. Cover with icing. Chill for at least 1 hour.