You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you today?

USER: I have reserved a ticket to meet my friend but suddenly it got postponed. So please help me with changing my reservation.

ASSISTANT: Sure, may I know your name please?

USER: I am Rebecca Williams.

ASSISTANT: Ok, please wait. Sorry, no active reservation found on your name to change.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you for reaching us, have a nice day.