You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: Myself Robert Jackson. Due to sudden change in my schedule, I would have to change my existing reservation. Could you help me in doing so?

ASSISTANT: Sure, I will help you with the change of flight reservation. Thanks for waiting, but sorry to say that there is no reservation on your name.

USER: Oh! That's fine, may be friend has changed it.

ASSISTANT: Ok, thanks for reaching to us.

USER: Thank you for your assistance.