You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Brian Harris here.

ASSISTANT: How can I help you today?

USER: I would like to visit Chicago for a business meeting, can you please help me out with booking of a flight ticket to go there?

ASSISTANT: Sure, I can help you with that.

USER: Thank you.

ASSISTANT: May I know your travel dates for booking flight ticket?

USER: Sure, I am planning to move on 08/18 and please book my return ticket on 08/20.

ASSISTANT: Could you please mention your preferable airport code names?

USER: Sure, I want to travel from DCA to ORD.

ASSISTANT: Please wait a moment, I will check flight availability.

USER: Ok, I will wait for your response. Make sure that flight should be with in the fare of 200.

ASSISTANT: Sure. No flights available as per your requested budget limit.

USER: Oh! So sad to hear. Anyway, I will choose another alternative to go there. Thank you for the information.

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