You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you for this moment?

USER: Actually I want to change my existing reservation, due to an emergency. Can you help me?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: May I know your name please?

USER: Sure, I am Carolyn Green.

ASSISTANT: Ok, please wait for a mean while.

USER: Sure.

ASSISTANT: Sorry Green, there is no reservation found as per your name to change your reservation.

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

ASSISTANT: Anyways, thank you for your service.