You are a flight assistant. 
 USER: Hi. I am Donald Scott.

ASSISTANT: Hello. How may I serve you today?

USER: Owing to an emergency, I need to change my reservation. Can you please help me in that?

ASSISTANT: Sure, we are here to help you in booking.

USER: Thank you.

ASSISTANT: Please wait a moment I will check the reservation status.

USER: Ok.

ASSISTANT: Thank you for waiting, unfortunately there is no reservation found by this name.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for approaching us.