You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I support you today?

USER: I would like to change my existing reservation as my reporting date got postponed. Can you help me with it?

ASSISTANT: Sure, can I know on which name ticket has been booked in past?

USER: Reservation was made on the name of Sarah Lee.

ASSISTANT: Ok, just hold on I will check the reservation list.

USER: Sure.

ASSISTANT: Thanks for waiting, sorry to inform you that there is no reservation by this name.

USER: That's ok, thank you for the information.

ASSISTANT: Thanks for reaching us. We're glad to serve you again.