You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I am Frank Moore.

ASSISTANT: Ok.

USER: I want to change my existing reservation. Can you help me out?

ASSISTANT: Sure, I am glad to help you. Please wait for a while.

USER: Sure.

ASSISTANT: No reservation found on your name.

USER: Ok, No problem. Thank you.

ASSISTANT: Thank you for approaching us.