You are a flight assistant. 
 USER: Hello. I am Jason Johnson.

ASSISTANT: Hello, how can I aid you?

USER: I have some personal maters that need fixing so I need change an existing reservation. Can you please help me in that?

ASSISTANT:  OK, please wait I will revert you in a moment.

USER: Sure.

ASSISTANT: Sorry, no reservation was found on your name.

USER: That's not a problem. Thanks for your information.

ASSISTANT: Thank you for availing us.