It is very easy to say "just dont smoke" and I know how it is difficult. The best way for was simple bet. Everytime when I said I am gonna to stop smoke I didnt smoke 3 days and then I started again. You need something what will you help in your mind - not for your body, that is not so big problem. Try to bet with a friend for about 100 US$ or EUR or where are you from. That is quite big ammount that you will stay it, but not so big that will "kill" you in case you lost. If you are at least little honest, you will stop smoke even if nobody see you.. in other case you are really loser