You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: Can you help me to change my reservation?

ASSISTANT: Sure, let me know your name please.

USER: I am Robert Perez.

ASSISTANT: Give me a moment.

USER: Sure.

ASSISTANT: Robert Perez. I regret to inform that that there is no reservation by your name.

USER: No problem, thank you for checking.

ASSISTANT: Thank you very much.