You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: Can you please book the ticket from DCA to IAD? As I need to take an exam regarding my documentary.

ASSISTANT: Sure, I am here to help you in booking. Can you please share your travel dates?

USER: I prefer to depart from my source location on 24th Feb and I want to return back by 26th Feb.

ASSISTANT: Ok, please share your name.

USER: My name is Nancy Carter.

ASSISTANT: May I know your connection limit?

USER: I need direct flight only.

ASSISTANT: Do you have any specification?

USER: I prefer major airlines to travel.

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

USER: Oh! That's ok, thank you for giving the information anyways.

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