You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I serve you?

USER: I have reserved a ticket to one place, but now venue is changed, so change my existing reservation.

ASSISTANT: Sure, may I know your good name?

USER: I am Mary Green.

ASSISTANT: Please wait a moment.

USER: Ok.

ASSISTANT: Thanks for waiting, no reservation found with your name.

USER: Thank you.

ASSISTANT: Thanks for connecting with us.