--- hi, How one become buisness system analyst if u have working exp on coding only. ---
One can never code unless and until one understands the whole requirement for the work to be done.Even if you are coding you need to know the impact of what you will be coding.Needless to say that you eventually gain/rather have to grasp the functional knowledge before you begin to code.
--- Do u have to be MBA for that? ---
Its not a compulsion to be a MBA to become buisness analyst.Some people have extensive knowledge of the specific domain to become buisness analyst.Though the functioning differs from client to client the basic concepts remain the same.