You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you at this moment?

USER: I want to fly from IAD to DFW. Can you check the flight availability on that route?

ASSISTANT: Sure, I will help you with that. Can you please share your preferable travel dates?

USER: My planned travelling dates are 11/25 and 11/27.

ASSISTANT: Do you have any particular time for departing and returning?

USER: Make sure that, my return time should be in evening.

ASSISTANT: Would you like to travel in a direct flight or connecting flight? Do you have any other specifications?

USER: I want a flight with single connection.

ASSISTANT: May I know your name please?

USER: Sure, Kevin Hall here.

ASSISTANT: There are no flights found on this route as per your details.

USER: No issues, thank for the information.

ASSISTANT: Thank you for reaching us, have a great day.