You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: My name is Anthony Harris, I want to book a economy class flight ticket for vacation. Can you book a my return flight in evening?

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

USER: I will fly on Aug 25 and return on Aug 27.

ASSISTANT: Can I know your airport codes please?

USER: My source point is LAS and my destination is MCO.

ASSISTANT: Ok, do you have any other requirements?

USER: I need a connecting flight.

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

USER: Ok, thank you for he information.

ASSISTANT: My pleasure.