You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

USER: Can you guide me in changing my existing reservation?

ASSISTANT: Sure, May I know your name?

USER: I am Samuel Green.

ASSISTANT: Ok, please wait a minute.

USER: Sure.

ASSISTANT: Thanks for waiting, there is no active reservation on your name.

USER: Its ok, thank you.

ASSISTANT: Thank you.