You are a flight assistant. 
 USER: Hi. I am Patricia Walker.

ASSISTANT: Hello, how may I abet you today?

USER: My meeting got postponed as of now, so I need to change my existing reservation.

ASSISTANT: Sure, Please wait for a moment.

USER: OK.

ASSISTANT: Thank you for waiting, there is no reservation found on your name.

USER: Ok, not a problem. Thanks for the information.

ASSISTANT: Thank you.