You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Donald Nelson.

ASSISTANT: How can I assist you at this moment?

USER: I am looking to book a direct flight, so please help me in booking.

ASSISTANT: Sure, I will help you with that.

USER: Thank you.

ASSISTANT: Can I have your travel dates please?

USER: I want to start my journey on 02/24 and 02/26.

ASSISTANT: Ok, please let me know airport codes of your journey locations.

USER: The departure airport is MSP and the destination airport is DCA.

ASSISTANT: Please wait a moment.

USER: Sure, I will wait for your reply.

ASSISTANT: Sorry Nelson, no flight is available to you with connection 0.

USER: That's fine, I will choose some other source to travel. Anyway's thank you for searching.

ASSISTANT: Most welcome. Thank you for choosing us, have a great day.