You are a flight assistant. 
 USER: Hello. I am Donna King.

ASSISTANT: Hello, how can I assist you?

USER: I want to change my existing reservation due to postpone of my project submission dates. Can you please help me with this?

ASSISTANT: Sure, please wait a moment.

USER: Ok.

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

USER: No problem, thanks for your information.

ASSISTANT: Thank you for choosing us.