Just commit to not drinking 'just for today'. If you never pick a drink up 'just for today' then you will never drink alcohol again. Simple...
I had to commit wholeheartadly to recovery from my alcoholism. This meant making everybody who needed to know that I am an alcoholic and now in recovery thus not drinking alcohol anymore. Period.
During the tough-times it makes your resolve much stronger when 'everybody' knows you as a non-drinker as how lousy are you gonna feel when they catch you drinking again?