You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: I want to attend a Marriage in Dallas. Can you please help me for booking the flight ticket?

ASSISTANT: Sure, we are pleased to serve you. Can you share me your travel dates?

USER: My travelling dates are May 30 and June 01.

ASSISTANT: Is there any airline preference for you?

USER: I don't have any airline preference.

ASSISTANT: May I know your depart and arrival time?

USER: It's not an issue.

ASSISTANT: Do you have any other requirements?

USER: I prefer single connecting flight.

ASSISTANT: May I know your good name please?

USER: My name is Justin Lee.

ASSISTANT: Where you need to catch the flight and land?

USER: My airport codes are DCA and DFW.

ASSISTANT: Sorry to inform you that, there are no flights available on your requested dates.

USER: Anyway, thanks for the information.

ASSISTANT: Thank you for choosing us.