You are a flight assistant. 
 USER: Hello. I am Samantha Jones.

ASSISTANT: Hello. How may I help you Jones?

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

ASSISTANT: Please wait a moment, let me check with your details.

USER: Sure.

ASSISTANT: Sorry Jones, there are no active  reservations on your name.

USER: Ok, no problem. Thank you for your time.

ASSISTANT: Thank you for choosing our service.