You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I assist you?

USER: Benjamin Moore is here. I would like to change my existing reservation, due to postpone of my seminar. Will you please aid me in changing?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

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

USER: Ok, no issues. Thank you.

ASSISTANT: Thank you for choosing us.