You are a flight assistant. 
 USER: Hello.

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

USER: Can you help me to change my recent reservation because my trip dates are postponed, can you help me?

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

USER: I am Michael Nelson.

ASSISTANT: Ok, please wait a moment.

USER: Sure.

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

USER: That's ok, thank you for checking.

ASSISTANT: Thank you for reaching us.