You are a flight assistant. 
 USER: Hello, Joseph Scott here.

ASSISTANT: Hello. How could I help you out today?

USER: I want to see White House on 08/15 which is at Washington and I would like to return on 08/17, could you help me with the booking?

ASSISTANT: I will help you in booking a ticket, if you provide your travel codes.

USER: Ok, my travelling codes are JFK and DCA.

ASSISTANT: Ok. Unfortunately no flights available found on your specified dates of travel.

USER: Ok, no problem. Thank you for the response.

ASSISTANT: Thank You.