You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: Can you help me in changing my recent reservation?

ASSISTANT: Sure, may I know your name?

USER: I am Joseph Harris.

ASSISTANT: Please give me a moment.

USER: Sure.

ASSISTANT: Sorry Joseph Harris, no reservation is available by your name.

USER: Its ok, thank you.

ASSISTANT: Thank you for reaching us.