Could you please tell me in the soccer or football by-laws as to the number or law number broken when you see an official actually drinking at a game he is supposed to officiating?

USSF answer (August 26, 2011):
IF by “drinking” you mean liquor or beer or ale, rather than water, iced tea, or soft drinks, then the referee has not broken any law or by-law, but has clearly violated Items 1, 2, 7, 8, 9, and 12 of the Referee Code of Ethics (contained in the Referee Administrative Handbook):

Code of Ethics for Referees
(1) I will always maintain the utmost respect for the game of soccer.
(2) I will conduct myself honorably at all times and maintain the dignity of my position.
(3) I will always honor an assignment or any other contractual obligation.
(4) I will attend training meetings and clinics so as to know the Laws of the Game, their proper interpretation and their application.
(5) I will always strive to achieve maximum team work with my fellow officials.
(6) I will be loyal to my fellow officials and never knowingly promote criticism of them.
(7) I will be in good physical condition.
(8) I will control the players effectively by being courteous and considerate without sacrificing fairness.
(9) I will do my utmost to assist my fellow officials to better themselves and their work.
(10) I will not make statements about any games except to clarify an interpretation of the Laws of the Game.
(11) I will not discriminate against nor take undue advantage of any individual group on the basis of race, color, religion, sex or national origin.
(12) I consider it a privilege to be a part of the U.S. Soccer Federation and my actions will reflect credit upon that organization and its affiliates.

In addition, the action may in fact be in violation of civil law, depending on where this occurred (it is public, it is in a public place, it may be on school or park grounds, etc., all of which may be controlled by various laws regarding the consumption of alcohol).