You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you?

USER: Please help me to change my recent reservation.

ASSISTANT: Sure, I am here to help you with that, can I know your good name to proceed further?

USER: Katherine Clark.

ASSISTANT: Thank you very much. Please wait for a while, let me check your reservation status in our database.

USER: Sure.

ASSISTANT: I am very sorry to inform you that there is no reservation found under your name in our database.

USER: Thank you for your information.

ASSISTANT: Thank you for reaching us.