You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, How can I serve you?

USER: Please help me to change my recent reservation.

ASSISTANT: Sure, May I know your name?

USER: Samuel Martin.

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: Sorry, No reservation found on your name.

USER: Thank you for your information.

ASSISTANT: Thank you for opting us.