You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: Due to bad weather conditions, I want to change my existing reservation. Can you help me out?

ASSISTANT: Sure, please wait a moment.

USER: Ok.

ASSISTANT: May I know your name please?

USER: Sure, my name is Elizabeth Johnson.

ASSISTANT: Sorry Johnson, there is no reservation found on your name.

USER: That's fine, thank you for the information.

ASSISTANT: Thank you for choosing us.