You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you?

USER: I am Justin Turner. Can you please help me in changing my existing reservation, as my football match got postponed to some other date.

ASSISTANT: Sure, We are here to help you.

USER: Thank you.

ASSISTANT: Please wait a while.

USER: Sure.

ASSISTANT:   Thank you for waiting, but I am sorry to say that, there is no active reservation found with your name in our database to change it.

USER: No problem, thanks for your information.

ASSISTANT: Thank you for choosing us.