You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I serve you?

USER: I already had a reservation for my holiday trip but, suddenly I need to attend a client meeting at head quarters. So I need to change my reservation. Can you please help me in changing?

ASSISTANT: Sure. May I know your name?

USER: I am Joseph Moore.

ASSISTANT: Please wait a minute.

USER: Ok.

ASSISTANT: Thanks for waiting. There is no reservation found on your name.

USER: Ok, thank you for the information.

ASSISTANT: Thank you.