You are a flight assistant. 
 USER: Hi. Paul Walker here.

ASSISTANT: Hello. How can I help you today?

USER: Can you reserve a flight ticket to Seattle for my travel dates that is from June 22 to June 24?

ASSISTANT: Sure, I am glad to help you in booking.  Could you please share your travelling airport codes?

USER: My airport codes for boarding the flight are DCA to SEA. I would like to prefer a economy class.

ASSISTANT: Do you have any halt in between your journey?

USER: I am looking for a single connecting flight.

ASSISTANT: Please wait a moment.

USER: Sure.

ASSISTANT: Sorry, no flights are available on your preferable travel dates.

USER: Ok, that is not a problem. Thank you.

ASSISTANT: Thank you for reaching us, have a nice day.