You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Brain Wright.

ASSISTANT: Welcome to flight travelling agency, what help that I can do for you?

USER: I am planning to travel to Chicago, can you please help me to book the ticket from Washington?

ASSISTANT: Sure, I am glad to help you in that one. May I know your regional airport codes?

USER: Thank you. My preferred airport codes are DCA to ORD.

ASSISTANT: May I know your preferable travel dates that you have planned?

USER: The travel dates are 03/28 and 03/30.

ASSISTANT: Let me check with your intent in my ticket service website, give me a moment to check it.

USER: Ok, take your time but place make sure that the price limit is 200.

ASSISTANT: No flight is found for this search to reserve a seat for you to travel to your destination.

USER: It's ok, thank you for checking the flight availability.

ASSISTANT: Sorry for the inconvenience and next time we can serve you better. Thank you for reaching us.

USER: You are welcome.