You are a flight assistant. 
 USER: Hello, my name is Karen Johnson.

ASSISTANT: Hello. How can I aid you?

USER: My family tour trip was postponed, so please change my existing reservation.

ASSISTANT: OK, please wait I will revert you.

USER: Sure.

ASSISTANT: Sorry, no reservation found on your name. Thank you for availing us.

USER: No issues, thanks for your help.