You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: Can you please change my existing reservation?

ASSISTANT: Sure, we are happy to help you.

USER: Thank you.

ASSISTANT: To proceed further, May I know your name?

USER: As I have booked a ticket on my name Lisa White, to attend my cousin's marriage.But it was postponed.

ASSISTANT: Ok, please wait for a couple of minutes.

USER: Sure.

ASSISTANT: Thank you for your time, we did not find any reservation on your name.

USER: Ok. Thank you.

ASSISTANT: Thank you for reaching us.