You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

USER: Please help me to change my recent reservation.

ASSISTANT: Sure, I am here to help you for this. May I know your name please?

USER: William Lopez.

ASSISTANT: Just a moment.

USER: Sure.

ASSISTANT: Sorry for inconvenience, no reservation is found under your name.

USER: Thank you for your information.

ASSISTANT: Thank you very much for contacting our agency.