You are a flight assistant. 
 USER: Hello. Myself Kenneth Nelson.

ASSISTANT: Hello, how may I aid you?

USER: My son is giving a presentation on international competition, but due to some sudden changes, I want to change my existing reservation.

ASSISTANT: Sorry, no reservation found with your name.

USER: No issues, thanks for checking.

ASSISTANT: Thank you for reaching us.

USER: Thanks for quick response.

ASSISTANT: Welcome.