You are a flight assistant. 
 USER: Hi. I am Jacob White.

ASSISTANT: Hello, how can I help you today?

USER: I would like to change my existing reservation, due to an emergency work my meeting has been postponed. Could you please avail me?

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

USER: Sure.

ASSISTANT: Thanks for waiting, no flight reservation found with you given name.

USER: Ok, no problem. Thank you for your valuable information.

ASSISTANT: Thank you for opting us.