You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I assist you?

USER: I am Amanda Campbell. I want to change my existing reservation, can you help me with that?

ASSISTANT: Sure, Please wait a second.

USER: Sure, take your time.

ASSISTANT: Sorry, No reservation found on your name.

USER: That's fine. Thank you for your service.

ASSISTANT: Thank you for availing us.