You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I serve you today?

USER: I want to change my existing reservation. Can you please help me with this?

ASSISTANT: Sure, we are here to help you.

USER: Thank you.

ASSISTANT: Please share your name to proceed for further.

USER: Sure, I am Kenneth Carter.

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: Sorry, there is no reservation on your name to change.

USER: Ok, no problem. Thank you for checking.

ASSISTANT: Thank you for availing us.