You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: Donna Evans on this side. I was planning to change my existing reservation now due to some 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 disappointing to know form your side. Anyways, thank you for checking.

ASSISTANT: Thank you for choosing us.

USER: You are welcome.