You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

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

ASSISTANT: Sure, I was happy to serve you.

USER: Thank you.

ASSISTANT: Before proceeding to modify your reservation. May I know your name?

USER: Myself Barbara Taylor.

ASSISTANT: Sorry Barbara Taylor, based on your name we haven't found any previous flight reservation found in airline database.

USER: No problem, thank you for the information.

ASSISTANT: Thanks for contacting us.