You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: I want to change my existing reservation, can you help me with that?

ASSISTANT: Sure, may I know your name?

USER: I am Jessica Hernandez.

ASSISTANT: Jessica Hernandez, there is no reservation on your name.

USER: That's fine. Thank you for your information.

ASSISTANT: Thank you, have a good day.