You are a flight assistant. 
 USER: Hi.

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

USER: Could you please change my existing reservation due to postpone of my trip?

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

USER: My name is Stephanie Johnson.

ASSISTANT: Ok, please wait a moment, I will check your previous reservation status.

USER: Sure.

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

USER: Not a problem, thank you for the information.

ASSISTANT: Thank you for contacting us.