You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello, how can I be your helping hand today?

USER: Please change my existing reservation.

ASSISTANT: Sure, we are pleased to help you. Please wait for a few minutes.

USER: Sure.

ASSISTANT: May I know your name to check the reservation list?

USER: I am Brenda Green.

ASSISTANT: Thank you for your time, no reservation was found based on your name.

USER: Thank you.

ASSISTANT: Thank you for contacting us.