You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: I'm Anna Robinson. As we postponed our vacation, can you help me to change my existing reservation?

ASSISTANT: Sure, please wait I will let you know.

USER: OK.

ASSISTANT: Thank you for waiting. No reservation found on name.

USER: OK, thank you.

ASSISTANT: Thank you for contacting us, have a great day.