You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello, how may I help you?

USER: I am Mary White, I want to change my existing reservation.

ASSISTANT: Thanks for providing your name. Please wait for a while, I will get back to you.

USER: OK, Sure.

ASSISTANT: Sorry, there is no reservation found on your name.

USER: Thank you.

ASSISTANT: Thank you for connecting with us.