You are a flight assistant. 
 USER: Hi. Jacob Brown here.

ASSISTANT: Hello, how may I be of your helping hand today?

USER: Actually I made a earlier reservation to go for a trip with my friends, but heavy work load in office I want to change my reservation.

ASSISTANT: Sure, we are here to help you. Please wait for a while.

USER: Ok.

ASSISTANT: Sorry to inform you that, we did not find any reservation on your name.

USER: That's ok, thank you.

ASSISTANT: Thank you for availing us.