You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, How can I assist you?

USER: Can you please help me to book a flight ticket from DCA to DEN?

ASSISTANT: Sure, May I know the travelling dates?

USER: My travelling dates are in Nov from 9th to 11th.

ASSISTANT: Do you have any connection limit?

USER: Yes, I need a single connecting flight.

ASSISTANT: Do you have any airline preference?

USER: No, I don't have any airline preference.

ASSISTANT: Is there any preference for departure and return timings?

USER: I would like to return with a morning flight.

ASSISTANT: May I know your name?

USER: Angela Rodriguez here.

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: Sorry, No flights found with your preferable dates.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you for availing us.