You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello, how may I help you?

USER: Please change my existing reservation owing to an emergency.

ASSISTANT: Ok, no problem. I will help you in changing. May I know your name to check your reservation status?

USER: My name is Jonathan Allen.

ASSISTANT: Sorry, no reservation has found with your name.

USER: Thank you.

ASSISTANT: Thank you for approaching us, have a nice day.