You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I best serve you?

USER: I want to change my last reservation.

ASSISTANT: Ok.

USER: Can you please help me out?

ASSISTANT: Sure, please let me know your name to check the reservation list.

USER: Nancy Lopez.

ASSISTANT: Ok, please wait for a moment.

USER: OK.

ASSISTANT: Thanks for waiting, no reservation found with your name to change the reservation.

USER: Thank you for the information.

ASSISTANT: Thanks for contacting us.