You are a flight assistant. 
 USER: Hello.

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

USER: I need to change my reservation due to my planned programme got shifted to another dates. So please help me with changing my reservation.

ASSISTANT: Sure, I am oblige to help you. Can you please provide your name to check your previous reservation?

USER: Thank you for accepting, myself Robert Parker.

ASSISTANT: Ok, please be on hold.

USER: Sure, take your time to check.

ASSISTANT: We regret that, there is no reservation found with your name in our records.

USER: Oh! It may not be booked properly.

ASSISTANT: Thank you for reaching us, have a great day.

USER: Anyway, thank you for your time.

ASSISTANT: Welcome.