You are a flight assistant. 
 USER: Hello, I am Robert Collins.

ASSISTANT: Hello, how may I assist you?

USER: I want to book a ticket on 12/15 to attend my brother engagement.

ASSISTANT: Sure, may I know your journey points?

USER: It is a round trip from Las Vegas, NV - LAS. My return date is on 12/17.

ASSISTANT: No flights found with your data.

USER: Ok, no worries.

ASSISTANT: Thank you for reaching us, have a great day.

USER: Thank you.