first no one is perfect. if he said he wanted to stop and continues, then he made a mistake. he is human. it really isn't fair for you to use your kid as a tool to make your husband stop using what research has proven to be one of the most addictive drugs, nicotine. I am with you on the lie thing but under the circumstances come on. If he is smoking behind your back then that's gotta say something about this drug. HE can't do it alone.
yeah the lying would bother me too. And he knows its a big deal to you or he wouldnt have lied. Go crazy inspector gadget on his a**. Smell his breath, all his clothes, his car every time he goes somewhere. Make it very difficult. He should get tired of that fast.
Also be helpful though. Buy gum, patches, subliminal tapes, whatever. Tell him you will do whatever you have to to save his life.
if not ultimadum time.