You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: My name is Amanda Scott. I would like to do some modification in my existing reservation, can you help me for that?

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

USER: Thank you.

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

USER: That's ok, thank you for checking.

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

USER: Welcome.