You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: Could you please help me in change an existing reservation?

ASSISTANT: Sure, may I know your name please?

USER: Sure, my name is Virginia baker.

ASSISTANT: Sorry, there is no reservation found under your name.

USER: OK, thank you.

ASSISTANT: Thank you for reaching us, have a good day.