You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, do you need any help from us?

USER: I am planning to visit Dallas in business flight from LAS, will you help me in booking the flight ticket?

ASSISTANT: Sure, could you please share your departure and arrival day?

USER: My preferable journey dates are Feb 28 and Mar 01.

ASSISTANT: Ok, could I have your name please?

USER: Myself Ronald Robinson.

ASSISTANT: Ok, do you need direct or connecting flight?

USER: I need a flight with single connection.

ASSISTANT: Ok, do you have any other specifications?

USER: I would like to depart in evening time.

ASSISTANT: Sorry, there is no flight on your requested travelling dates.

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: You are welcome, have a great day.