You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I serve you?

USER: Please reserve me a flight ticket from DCA to LAX.

ASSISTANT: Sure, May I know the travelling dates?

USER: My travel dates are Apr 03 and Apr 05.

ASSISTANT: Do you have any connection limit?

USER: I prefer connecting flight for this trip.

ASSISTANT: Is there any other requirements?

USER: I would like to prefer normal cost airline.

ASSISTANT: May I know your name?

USER: I am Brian Robinson.

ASSISTANT: Please wait a minute.

USER: Sure.

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

USER: No problem, thank you for the information.

ASSISTANT: Thank you for opting us.