I'd an interview 1 week ago, the people are nice, but l do not wanna go anymore, because the firm is too small and l think it is the best for me to stay in my old firm becuase of the economy.

they were very interested during interview and told me they will know after a week. should l still email them my decision or wait till them to contact me, if not, drop it?

thanks.

Wait for them to call u, why send and email if they are not going to offer you a job?

l would wait for them to contact you.
You never know what may happen in the future.

yes - in this case l would email a thank you letter and let them know that you have accepted another offer. let them know how much you appreciate their time and meeting them to leave a good impression.

it will save them time in case they are considering you.

l think you should wait until they call you. You may decide after all to take the job, if it is a really good offer. You do not want to look unprofessional and burn bridges later on, you never know!!!

Go ahead and email them. That way they can quickly make a decision for the next people in line. It is the professional thing to do.