You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, may I know your good name please?

USER: I am Jennifer Wright.

ASSISTANT: How can I assist you?

USER: Could you please change my existing reservation as my meeting has been postponed?

ASSISTANT: Sure, please wait for a minute I will check and revert you.

USER: Sure.

ASSISTANT: Thanks for waiting, I am sorry to say there is no reservation found on your name.

USER: Not a problem. Thank you for the information.

ASSISTANT: Thanks for choosing us, have a great day.