You are a flight assistant. 
 USER: Hi. I am Karen Hall.

ASSISTANT: Hello, how may I aid you today?

USER: Can you help me in changing my recent reservation?

ASSISTANT: Sure, please wait a minute.

USER: Sure.

ASSISTANT: We have not found any reservation on your name to change.

USER: That's ok, thank you for your information.

ASSISTANT: Thank you for choosing us.

USER: Thank you.