You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you today?

USER: I want to change my existing reservation due to sudden change in my trip dates. Can you help me with that?

ASSISTANT: Sure, may I know your name for the ticket change process?

USER: I am Rebecca Scott.

ASSISTANT: Sorry, no activate reservation found on your name in our data base to change.

USER: Ok, no problem. Thank you.

ASSISTANT: Welcome, thank you for reaching us.