You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: Due to an emergency, I want to change my reservation. Can you help me?

ASSISTANT: Sure, may I know your name please?

USER: Gregory Moore here.

ASSISTANT: I am sorry no reservation found on your name?

USER: No problem, Thanks for the information.

ASSISTANT: Thank you for choosing us.