You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you?

USER: I want to book a ticket from ORD to LAS. Could you book a ticket?

ASSISTANT: Sure, may I know your trip dates please?

USER: Departure is Mar, 30 and return date is Apr, 1.

ASSISTANT: Do you have any other requirements?

USER: I would prefer direct flight.

ASSISTANT: Can I know your name please?

USER: My name is Jerry Anderson.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

ASSISTANT: Sorry, we regret to inform you that there is no flight available as per your request.

USER: Thank you.

ASSISTANT: Most welcome.