You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello. How may I help you today?

USER: Please change my existing reservation.

ASSISTANT: Sure, may I have your name please?

USER: I am Kathleen Perez.

ASSISTANT: Ok, please wait a moment.

USER: Sure.

ASSISTANT: I searched your name in our database, but it could not found.

USER: Thank you.

ASSISTANT: Thank you for reaching us.