rahul and Abhishek,
Aaahhhhhhhh, smoking.
A couple of things might help.
First switch to an organic type cigarette for awhile (a brand that doesn't use chemicals in the growing process, manufacturing process, or in the paper they use) There are some out there though they might not be easy to find. This will help get you off of the chemical addictions and will improve other aspects of your health. (will cut down or stop 'smoker's cough' for instance)
After you have done that (give it a couple of months) and decide it is time to stop completely avoid people who smoke (this is really important and is the primary reason I haven't been able to stop since my husband is a heavy smoker and shows no interest in quitting).
Beyond the usual things that you will read to help assist in quitting those are my reccommendations.
Good luck to both of you.