You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you at this moment?

USER: I want to change my existing reservation. Can you please help me in that?

ASSISTANT: Sure. I will help you with that. May I know your name for further process?

USER: Myself Paul Adams.

ASSISTANT: Ok, please wait a moment.

USER: Sure.

ASSISTANT: There is no previous reservation available under your name.

USER: Ok, no problem. Thank you for your information.

ASSISTANT: Thank you for reaching us.