You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: I am planning to visit my school friends parents at Chicago. Help me in booking my flight ticket with fare of 200.

ASSISTANT: Sure, may I know your good name please?

USER: Robert Wright here.

ASSISTANT: May I know your travelling dates, please?

USER: My travelling days are from 12/30 to 01/01.

ASSISTANT: May I know your travelling airport codes please?

USER: My travelling airport codes are from LAX to ORD.

ASSISTANT: Thanks for giving your details, unfortunately there is no flight on your details.

USER: That's ok ,thank you for your assistance.

ASSISTANT: Thanks for choosing us.