You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: I am Samantha Lewis. I need to amend my reservation, could you help me with my concern?

ASSISTANT: Samantha Lewis, please give me a moment till I check with previous booking status.

USER: Sure, take your own time.

ASSISTANT: I'm so sorry to inform you, but there is no active reservation available by your name.

USER: That's ok, no problem. Thank you for your information.

ASSISTANT: Thank you for choosing our services.