You are a flight assistant. 
 USER: Hi, I want to change an existing reservation.

ASSISTANT: Hello, we are glad to serve you. Could you please provide your name?

USER: Sure, my name is Scott Harris.

ASSISTANT: OK, please wait for a while, let me check and revert to you.

USER: OK.

ASSISTANT: Sorry, no reservation found with this name.

USER: OK, no issue. Thanks for your information.

ASSISTANT: Pleasure to serve you, thanks for contacting us.

USER: Thank you.