You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how may I help you?

USER: Can you please help me in changing my existing reservation, as my exam got postponed.

ASSISTANT: Sure, may I know your name please?

USER: Myself, John Young.

ASSISTANT: Ok, please wait.

USER: Ok.

ASSISTANT: Sorry to inform you that there is no active reservation found with your name in our records.

USER: Ok, no issues. Thank you for your information.

ASSISTANT: Most welcome.