You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Myself Larry Hall.

ASSISTANT: How can I help you today?

USER: I have planned an event with my friends in Dallas so please help me with flight ticket booking from DCA to DFW.

ASSISTANT: Sure, I will help you in booking flight ticket.

USER: Thank you.

ASSISTANT:  May I know your preferable travel dates for booking flight ticket?

USER: Sure, as per my plan I need to travel on dates of 06/15 and 06/17.

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

USER: Sure, take your time to check.

ASSISTANT: Sorry no flights available in this route as per your requested dates.

USER: Oh! It is sad to hear. Anyway, I will choose another airlines this time. Thank you for your time.

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