You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I am Donna Anderson.

ASSISTANT: Ok.

USER: I want to change my reservation, can you help me?

ASSISTANT: Sure, please wait for a moment, I will check and get back to you.

USER: Sure.

ASSISTANT: Sorry, there was no reservation found with your name.

USER: Ok, thanks for information.

ASSISTANT: Thank you for choosing us.