You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello,. How can I support you the best now?

USER: Due to some personal work, I want to change my existing reservation.

ASSISTANT: Sure, I will help you with that. On what name, do I need to check your reservation?

USER: Please check the reservation on the name of Sarah Baker.

ASSISTANT: Please wait, let me check and revert you the present status.

USER: Sure.

ASSISTANT: Thanks for waiting. Sorry to say that, no reservation was found with your good name.

USER: Ok, Thank you for your service.

ASSISTANT: Thanks for your presence.