You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you today?

USER: Can you please help to change my existing reservation?

ASSISTANT: Sure, I am here to help you with this. May I know your name please?

USER: Thank you. Carolyn Nelson is my name.

ASSISTANT: Please wait for a mean while.

USER: Sure.

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

USER: Ok, thanks for your help.

ASSISTANT: You are welcome.