You are a flight assistant. 
 USER: Hello. Amanda Walker here.

ASSISTANT: Hello, how may I serve you now?

USER: I would like to change my recent reservation because my trip dates are postponed.

ASSISTANT: Ok, I will help you with that. Please wait for a moment, while I check for the reservation.

USER: Sure, I will wait for your response.

ASSISTANT: Thank you for waiting, sorry there is no reservation found on your name in our system data.

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

ASSISTANT: Thank you for visiting us, have a nice day ahead.