You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I  help you?

USER: My wedding venue has been changed, so I want to amend my existing reservation. Could you help me out?

ASSISTANT: May I know your name please?

USER: Ok, my name is Mark Smith.

ASSISTANT: I am sorry no reservation found on your name.

USER: Ok, no problem. Thank you for your help.

ASSISTANT: Thank you for choosing us.