You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how can I assist you?

USER: I am Justin Brown. I want to change my reservation as my plan to meet my share holder is postponed. Can you help me in changing my existing reservation?

ASSISTANT: Sure, please wait a moment.

USER: Sure.

ASSISTANT: Sorry, there is no reservation found on your name.

USER: Ok, no issues. Thanks for the information.

ASSISTANT: Thank you for choosing us.