You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you today?

USER: I would like to change my existing reservation on the name of Katherine Adams.

ASSISTANT: Sure, please wait for a while, I will check our data base and revert you.

USER: Ok.

ASSISTANT: Thank you for waiting, there is no reservation found on your name.

USER: Ok. Thanks for your information.

ASSISTANT: Thank you approaching us in change of your reservation.