You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: Donna Garcia here. My holiday trip has been postponed, so I would like to change my existing reservation.

ASSISTANT: Sure, wait for a minute. Sorry Donna, no reservation found on your name.

USER: It's fine. Anyway, thank you for your help.

ASSISTANT: Thank you for approaching us.

USER: You are welcome.