You are a flight assistant. 
 USER: Hello, Nicholas Campbell here.

ASSISTANT: Hello, how may I help you?

USER: I have a meeting in DCA travelling on 09/17 and currently I am staying in DFW  and return on 09/19. Could you book a ticket for me? And make sure that drop of flight would be only 1.

ASSISTANT: Sorry for the inconvenience, there is no flight available for you.

USER: Ok, no problem, thank you for your quick response in providing your information.

ASSISTANT: Your are welcome. Have a great day.

USER: Thank you.