You are a flight assistant. 
 USER: Hello, I am Michael Baker.

ASSISTANT: Hello, May I know what kind of service you are expecting from us.

USER: As my live concert was postponed, I want to change my existing reservation.

ASSISTANT: Ok, please wait for a minute, I will revert to you.

USER: Ok.

ASSISTANT: Sorry, there is no reservation found with your name. Thank you for availing us.

USER: No problem, Thank you for the information.