You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello, how may I support you?

USER: Please change existing reservation.

ASSISTANT: Sure, may I know your good name?

USER: I'm Kathleen Harris.

ASSISTANT: Please wait for a moment while I check for the reservation.

USER: Ok.

ASSISTANT: Thanks for waiting, Sorry Harris there is no any reservation on your name is found.

USER: Thanks.

ASSISTANT: Thank you have a nice day.