You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Myself Katherine Brown.

ASSISTANT: How may I help you?

USER: Due to the postponement of a match held in Austin, I would like to change my existing reservation. Could you help me out with this?

ASSISTANT: Sure Brown, I am here to help you. Wait a moment.

USER: Ok.

ASSISTANT: Sorry, there is no reservation found for you.

USER: That's ok. Thank you.

ASSISTANT: Welcome, thank you for choosing us.