You are a flight assistant. 
 USER: Hello, I am Amy Clark.

ASSISTANT: Hello, how can I assist you today?

USER: Due to sudden changes my meeting has been cancelled. I want to change my existing reservation. Can you please help me with it?

ASSISTANT: Sure. Please wait for a minute.

USER: OK.

ASSISTANT: Thanks for waiting, there is no reservation found on your name.

USER: Not a problem, thank you.

ASSISTANT: Thank you for choosing us.