You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I assist you today?

USER: I am Lisa Wright,I want to change my existing reservation.

ASSISTANT: OK, Lisa Wright, Wait for a moment. Thank you for waiting, We did not find any existing reservation on your specified name.

USER: All right, I will wait.

ASSISTANT: Thanks for contacting us.

USER: OK, thank you for your information.

ASSISTANT: Have a nice day.