You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Samantha Walker.

ASSISTANT: How may I help you out?

USER: I need to amend my reservation, can you help me out?

ASSISTANT: Sure, I will help you in changing the reservation.

USER: Thank you.

ASSISTANT: Sorry, there are no reservations found.

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

ASSISTANT: Thank you for choosing us.