You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you today?

USER: Please help me in changing of my existing reservation.

ASSISTANT: Sure, may I know your name?

USER: Linda Young.

ASSISTANT: Please wait for couple of minutes.

USER: Sure.

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

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for contacting us.