You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello. How can I assist you?

USER: Please change my existing reservation.

ASSISTANT: Ok, sure. May I know your name?

USER: I am Laura Gonzalez.

ASSISTANT: Ok, please wait.

USER: Sure.

ASSISTANT: Sorry, no reservation found on your name to change.

USER: Thank you.

ASSISTANT: Most welcome.