You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Stephanie Martin.

ASSISTANT: How can I help you Stephanie today?

USER: I would like to book a ticket from TX-IAD to CO-DEN. Can you please book  a ticket for me?

ASSISTANT: Sure, I can help you with that. Could you please mention your travel dates for booking flight ticket?

USER: My travelling dates are 12/19 and return back on 12/21.

ASSISTANT: Just give me a moment, I will check flight availability.

USER: Make sure my price limit is 200. Sure, take your own time.

ASSISTANT: Sure. Sorry for the inconvenience, no flights available as per your requested dates.

USER: That's fine. Thank you for your help.

ASSISTANT: Thank you for reaching us, have a good day.