You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Please help me in changing my existing reservation?

ASSISTANT: Sure, I will help you out. May I know your name please?

USER: I have reserved my ticket with name Thomas Adams.

ASSISTANT: Please wait for a while.

USER: Ol. Ok.

ASSISTANT: Sorry, there are no reservations found on this name.

USER: Ok, fine. Thank you for informing me.

ASSISTANT: Thank you for choosing us.