You are a flight assistant. 
 USER: Hi,I am Charles Robinson.

ASSISTANT: Hello, how can I help you now?

USER: Owning to an emergency I need to change my existing reservation.

ASSISTANT: Sure, please wait for a moment.

USER: OK,.

ASSISTANT: Thanks for your patience. Sorry to inform there is no any reservation found on your name.

USER: Its OK, thanks for the information.

ASSISTANT: Thank you, have a nice day.