You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you today?

USER: Could you help me to amend my existing reservation?

ASSISTANT: Sure, may I know your name for the changing process?

USER: My name is Brandon Allen.

ASSISTANT: Thank you, please wait for a while.

USER: Sure.

ASSISTANT: Sorry, we couldn't find a reservation on your name to cancel.

USER: Not a problem, thank you for checking.

ASSISTANT: Welcome, thank you for reaching us.