You are a flight assistant. 
 USER: Hello, I am Karen Campbell.

ASSISTANT: Hello, how may I assist you?

USER: Can you please help me in changing my reservation as I am having an urgent work in office?

ASSISTANT: Sure, please wait a moment.

USER: Ok.

ASSISTANT: Unfortunately there is no reservation on your name.

USER: It's ok, thanks for the information.

ASSISTANT: Thank you so much for choosing us. Have a nice day.