You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I am Steven Scott. Owning to an emergency, I would like to change my existing reservation. Can you please help me with this?

ASSISTANT: Sure, I will help you to cancel your reservation.

USER: Please change my reservation.

ASSISTANT: Sure, I will help you to change your reservation.

USER: Thank you.

ASSISTANT: Please give me a moment.

USER: Ok.

ASSISTANT: Sorry, no reservation found on your name to change your reservation.

USER: Ok, no problem. Thank you for the information.

ASSISTANT: Welcome, have a nice day.