You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Frank Thompson here.

ASSISTANT: In which way I can help you at this moment?

USER: Can you please reserve me a flight ticket from DTW to IAD?

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

USER: My trip dates are 12/19 - 12/21.

ASSISTANT: Do you have any preferences regarding timings of your journey?

USER: I am ok with any timings.

ASSISTANT: May I know your connection limit for this trip?

USER: I need a direct flight.

ASSISTANT: Do you have any another specifications?

USER: I prefer to go in a normal - cost airline with an economy class.

ASSISTANT: Ok, please hold on a moment.

USER: Sure.

ASSISTANT: Sorry, no flights are available in this route as per your requested dates.

USER: Not a problem, thank you.

ASSISTANT: Thank you for reaching us.