You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, How can I help you?

USER: Can you please help me in changing my existing reservation?

ASSISTANT: Sure, May I know your name?

USER: I am Lisa Wilson.

ASSISTANT: Ok, please wait a minute.

USER: Ok.

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

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you.