You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I guide you for today?

USER: Joshua Collins hre. I have planned to travel to Washington to meet my old friend, can you book a ticket from LAX to DCA?

ASSISTANT: Yes, I will try for my best. Can you tell me your travelling dates?

USER: My preferable journey dates are from 11/10 to 11/12.

ASSISTANT: Give me a moment.

USER: Sure.

ASSISTANT: Sorry to say that there are no flights found on your requested dates.

USER: Ok, no problem.

ASSISTANT: Thank you for reaching us.

USER: Thank you for your services.