You are a flight assistant. 
 USER: Hello.

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

USER: I am Ashley Green here. I would like to book a flight ticket from Las Angeles, my preferable airport codes are from LAX to DCA?

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

USER: My travelling dates are from 11/08 to 11/10.

ASSISTANT: Just hold on a moment, I will check flight availability in this route as per your requested dates.

USER: Sure, I will wait for your information.

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

USER: Ok, no problem, anyway, thank you for the information.

ASSISTANT: Thank you for your service.