You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you today?

USER: I am Ryan Nelson. I need to change my recent reservation due to postpone of my exam. Could you please help me in doing that?

ASSISTANT: Sure, I'll help you in change an existing reservation.

USER: Thank you.

ASSISTANT: Please wait a moment I will check the reservation status.

USER: Sure.

ASSISTANT: Thank you for waiting, unfortunately there is no reservation found by your name.

USER: No issues, thank you for your information.

ASSISTANT: Thank you for opting us.