You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I want to change my existing reservation, as my health is not good to travel. Can you please help me with this?

ASSISTANT: Sure, can you help me with your name to proceed?

USER: I am Brandon Lewis.

ASSISTANT: Sorry, there is no reservation found on your name.

USER: Ok, no problem. Thank you for your time.

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