You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I assist you now?

USER: Can you please help me to book flight ticket from IAD to DFW?

ASSISTANT: Sure, I am glad to help you with that. Can you please provide your preferable dates of travelling?

USER: My trip dates are Mar 3 and Mar 5.

ASSISTANT: Do you have any connection limit?

USER: I prefer a connecting flight.

ASSISTANT: Any more specifications do you have?

USER: I do not have any other specifications.

ASSISTANT: May I know your name to book the flight ticket?

USER: I am Anthony Adams.

ASSISTANT: Please wait a moment to check the flights.

USER: Sure.

ASSISTANT: We are apologize that, there are no flights running towards your region with your requested dates of travelling.

USER: It's ok, thank you.

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