You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how can I serve you today?

USER: Owing to an emergency, I need to change my reservation. Can you please help me in reservation?

ASSISTANT: Sure, for further process, May I know your name?

USER: I am Brian Baker.

ASSISTANT: Ok, please wait for a minute, while I will check and let me know and revert you.

USER: Ok.

ASSISTANT: Thank you for waiting. We are sorry to inform you, there is no reservation found against your name.

USER: Ok, no problem. Thanks for the information.

ASSISTANT: Thank you for choosing us. Have a great day.