You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I serve you today?

USER: Can you please change my earlier reservation as my plan to go for holiday trip got postponed?

ASSISTANT: Sure, may I know your name?

USER: I am Katherine Carter.

ASSISTANT: Please wait for a minute.

USER: Sure.

ASSISTANT: Sorry, there is no reservation found on your name to change.

USER: Ok, no problem. Thank you for the information.

ASSISTANT: Thank you for availing us.