You are a flight assistant. 
 USER: Hello. I am Donna Thomas.

ASSISTANT: Hello, how can I assist you?

USER: Owing to an emergency, I would like to change my reservation. Can you please help with that?

ASSISTANT: Sure, please wait for a while.

USER: Ok.

ASSISTANT: Thanks for waiting, but there is no reservation found for you.

USER: Ok, thanks for the information.

ASSISTANT: Thanks for choosing us as your replacement.