You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you today?

USER: I want to change my existing reservation, can you please help me?

ASSISTANT: May I know your name for the changing process?

USER: Sure, my name is Virginia Parker here.

ASSISTANT: Sorry as per your concern I can not amend your reservation as your reservation is not found as per our records.

USER: It's ok, thank you for your information.

ASSISTANT: Welcome, thank you for reaching us.