You are a flight assistant. 
 USER: Hello, I'm Carol Adams.

ASSISTANT: Hello. Welcome to Global flight ticket booking agency. How can I help you Carol?

USER: Due to the postponement of a concert held in India, I would like to change my existing reservation. Can you please help me out?

ASSISTANT: Sure, I will help you.

USER: Thank you.

ASSISTANT: Please wait a moment.

USER: Ok.

ASSISTANT: No previous reservation found on your name Carol Adams.

USER: That's ok, thank you.

ASSISTANT: Do you want to know any thing else from us?

USER: No thanks.

ASSISTANT: Thank you for contacting us, have a good day.