You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I support you today?

USER: I am unable to change my existing reservation in online so, I need your support in changing my reservation.

ASSISTANT: Sure, please mention your name to change it.

USER: Ok, my name is Larry Wright.

ASSISTANT: Thanks for your name, please standby.

USER: OK.

ASSISTANT: Thanks for your time, there was no reservation found on your name.

USER: Ok, that's not a problem. Thanks for the information.

ASSISTANT: Thank you for availing us.