You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you now?

USER: Can you please help me in reserving a flight ticket to IAD from DCA?

ASSISTANT: Sure, please share me your planned journey dates?

USER: My preferred travel dates are from May 24 to May 26.

ASSISTANT: Please mention your connection limit?

USER: I need a single connecting flight.

ASSISTANT: Do you have any preference related to flight timing?

USER: No, I do not have any specific timings.

ASSISTANT: Do you have any other requirement?

USER: I would like to travel in business class.

ASSISTANT: May I know your good name?

USER: I am Mark Phillips.

ASSISTANT: Thank you for the details, sorry there is no any seat is available in business class in any flight.

USER: Ok, no problem. Thank you.

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