You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you out?

USER: I want to change my existing reservation, due to postpone of my examination. Can you help me out?

ASSISTANT: Sure,may I have your name?

USER: Myself Cynthia Collins.

ASSISTANT: Ok, please hold for a while.

USER: Sure.

ASSISTANT: Unfortunately, in our database your name does not exist with reservation to change further.

USER: Ok, not an issue. Thank you for your kind information.

ASSISTANT: Thank you for reaching us.