You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: Kathleen Nelson here. I want to travel from Washington to Orlando for attending a Seminar. Can you please help me for booking the flight ticket?

ASSISTANT: Sure Kathleen Nelson, I will help you with that ticket booking. could you please provide me your travel dates?

USER: My travelling dates are from 05/18 to 05/20.

ASSISTANT: May I know your source and destination codes for booking your ticket?

USER: My airport codes are from IAD to MCO.

ASSISTANT: Please hold for a moment. Sorry to say, there are no flights available as per your travel dates.

USER: Anyway, thanks for the information.

ASSISTANT: Thank you for choosing our agency, have a nice day.