You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: I need to change my existing reservation, can you help me in doing that?

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

USER: I am Katherine Lopez.

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

USER: Ok, no issues. Thank you for the information.

ASSISTANT: Thank you for reaching us.