You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: I am planning to meet my brother at Washington, will you help me in booking the flight ticket from ORD to DCA?

ASSISTANT: Sure, I am here to help you for this. When are you planning your trip?

USER: My preferable journey dates dare Nov 10 and Nov 12.

ASSISTANT: May I know your name please?

USER: Myself Mark Thompson.

ASSISTANT: Is there any connection limit?

USER: I need a flight with single connection.

ASSISTANT: Do you have any other specifications regarding your journey?

USER: I prefer to travel in economy class which returns in evening time.

ASSISTANT: Sorry for inconvenience, no flights are found with your specifications.

USER: Ok, not an issue.

ASSISTANT: Thank you very much for approaching our agency.

USER: Thank you for your information.