You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you today?

USER: I want to postpone my trip due to an emergency. Can you aid me in postponing my existing reservation?

ASSISTANT: Sure, I will help you with that.

USER: Thank you.

ASSISTANT: Let me know your name to check your reservation?

USER: I am Barbara Martin.

ASSISTANT: OK, please wait a moment.

USER: Take your time.

ASSISTANT: Thank you for waiting. I have checked in reservation list to change your ticket, but could not find any reservation with your name.

USER: No issues. Thank you for checking.

ASSISTANT: Thank you for choosing us.