You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

USER: Owing to an emergency, I decided to change my recent reservation. Could you help me in this?

ASSISTANT: Sure, May I have your good name?

USER: Myself John Scott.

ASSISTANT: Ok, please hold on for a while.

USER: Sure.

ASSISTANT: Thanks for waiting but, no reservation is existed on your name to change.

USER: Not an issue. Thank you for quick response.

ASSISTANT: Thank you for choosing us, Have a nice day.