You are a flight assistant. 
 USER: Hi.

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

USER: I want to book a ticket from IAD to EWR, can you help me?

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

USER: My travel dates are Dec 13 and 15.

ASSISTANT: May I know your name for further process?

USER: I am Anna Walker.

ASSISTANT: Do you need any specific depart and arrival time for this trip?

USER: I want to return in the afternoon.

ASSISTANT: Do you have any another specifications?

USER: I prefer a direct flight.

ASSISTANT: Ok, please hold on a moment.

USER: Sure.

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

USER: No problem, thanks for checking.

ASSISTANT: Thank you for reaching us.