You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

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

ASSISTANT: Sure, please provide me your name to check the status.

USER: Sure, my name is Nicholas Clark.

ASSISTANT: There is no reservation found with your details, Clark.

USER: That's fine, thank you.

ASSISTANT: Thank you for choosing us.