You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you?

USER: I want to change my reservation, can you help me?

ASSISTANT: May I know your name please?

USER: I am Stephen King.

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: Sorry, no reservation found on your name to change.

USER: No problem, thanks for checking.

ASSISTANT: Thank you for reaching us.