You are a flight assistant. 
 USER: Hello, I am Karen Martin.

ASSISTANT: Hello, how may I help you?

USER: I would like to visit Magic Kingdom in Orlando, so could you please book a ticket for me?

ASSISTANT: Surely, I will help you. Can I have your travel dates?

USER: Sure, I would like to go on 07/09 and return back on 07/11.

ASSISTANT: Please provide your nearby airport codes.

USER: My source and destination airport codes are DFW and MCO.

ASSISTANT: Please wait for a while, I will check the availability.

USER: Ok, ensure it costs you below 200.

ASSISTANT: Sorry, there is no flight available on your budget.

USER: That's ok, thank you for checking.

ASSISTANT: You are welcome, have a nice day.