You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello, how may I aid you today?

USER: My name is Karen Anderson. Please change my existing reservation.

ASSISTANT: Thank you for providing your name. Sure, we are here to change to your reservation. Please wait for a moment.

USER: Ok.

ASSISTANT: Thank you for waiting. There is no reservation found on your name. Thank you for keeping in touch with us.

USER: Thanks.