You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: Cynthia Johnson here. I want to change my existing reservation now due to sudden office work. Can you help me?

ASSISTANT: Sure, please wait for a moment.

USER: Sure.

ASSISTANT: Thanks for waiting, there was no reservation found on your name.

USER: Oh! That's very sad to know. Anyways, thank you for checking.

ASSISTANT: Thank you for choosing us.

USER: You are welcome.