You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: My holiday vacation has been postponed.Can you please help in changing the existing reservation?

ASSISTANT: Could you please share your name?

USER: Sure, my name is Robert Turner.

ASSISTANT: Please wait for a moment.

USER: Ok.

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

USER: Ok. It's fine. Thank you for your information.

ASSISTANT: Thank you for choosing us. Have a great day.