Again this is a trap.Interviewer is trying to find out somthing negative about you.Never say that. Also never say that You do not have a weekness because there is no fun in that answer. Be prepared and rehearshed for this question. One of the best way to answer this question is to wrap one or two of your strenths or general habit as weekness and discuss it in brief. An Ideal weekness to make your interview happy could be "I am probably too passiomate about my work and do not spare enough time for my family"