You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

USER: I am George Clark. As I have fallen sick suddenly due to bad weather, I would like to change my recent reservation. Can you help me?

ASSISTANT: Sure, I will help you.

USER: Ok.

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

USER: That's ok, thank you.

ASSISTANT: Thank you for opting us.