You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you?

USER: I am Ronald Nelson. I would like to visit DCA, can you please book a flight ticket from EWR?

ASSISTANT: Sure, can you share your travel dates please?

USER: Sure, my journey dates are 10/15 and 10/17.

ASSISTANT: Thanks for waiting. But I am sorry to say that there are no flights available.

USER: That's ok, no problem.

ASSISTANT: Thank you.

USER: Thank you for your service.