You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you today?

USER: Due to some personal work, I want to change my existing reservation.

ASSISTANT: Ok. I will help you. Please share your name.

USER: Sure, I am Richard Thomas.

ASSISTANT: Please wait, I will revert to you.

USER: Sure.

ASSISTANT: No reservation is done to change.

USER: Ok, Thank you for providing information.

ASSISTANT: Thank you for choosing us.