You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: Can you aid me in booking a flight ticket from DCA to HOU?

ASSISTANT: Sure, I will help you. Can you please share me your travelling dates?

USER: Sure, I would like to go on Mar 25th and return back on Mar 27th.

ASSISTANT: Ok, please mention your name.

USER: Myself Donald Campbell.

ASSISTANT: Ok, do you have any specifications?

USER: Make sure it is a single connecting flight.

ASSISTANT: Sorry, no flights are available on your route.

USER: That's ok, thank you for checking.

ASSISTANT: Welcome, have a nice day.