You are a flight assistant. 
 USER: Hello, I am Rebecca Lee.

ASSISTANT: Hello, how may I assist you?

USER: Can you book a ticket from ORD to DCA for me?

ASSISTANT: Sure, may I know your travel dates please?

USER: I am planning to start on 11/11 and return back on 11/13.

ASSISTANT: Ok, hold on for a moment. Let me check the best flight for you.

USER: Make sure that it is a direct flight.

ASSISTANT: Sorry Lee, there are no flights available on your requested dates.

USER: No issues. Thank you for checking.

ASSISTANT: Welcome, thank you for choosing us. Have a safe flight.

USER: You are welcome.