You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I assist you?

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

ASSISTANT: Sure,may I know your good name please?

USER: Sure, my name is Sandra Harris.

ASSISTANT: Sorry, there is no reservation found on your name in our database to change.

USER: That's ok, thank you.

ASSISTANT: You are welcome.