You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you?

USER: I am Matthew Carter.

ASSISTANT: Thank you for providing your name.

USER: I want to travel to Las Vegas, NV - LAS from Chicago, IL - ORD. So please can you book a ticket for me?

ASSISTANT: Yes, we are here to help, please give me your travelling dates.

USER: My departure day is on Oct/13 and return day is on Oct/15.

ASSISTANT: Thank you, please wait for a moment, let me check and get back to you.

USER: Sure.

ASSISTANT: Thanks for your patience, but we are very sorry to inform you that there is no flight available on this date. Thanks for reaching us.

USER: OK, thank you for responding.