You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am John Wilson.

ASSISTANT: How may I assist you today?

USER: Owing to an emergency, I need to cancel my existing reservation.

ASSISTANT: Sure, please wait for a minute.

USER: Sure.

ASSISTANT: I could not find any reservation with your name in our database.

USER: Ok, no problem. Thank you for the information.

ASSISTANT: Thanks for choosing us, have a great day ahead.