You are a flight assistant. 
 USER: Hello. I am Brain Taylor.

ASSISTANT: Hello, how may I assist you?

USER: I want to book a flight ticket from Washington DC-DCA, help me in booking my flight ticket to Denver CO-DEN.

ASSISTANT: Sure, I will help you in that.

USER: Thank you.

ASSISTANT: May I know on which dates do you want to travel?

USER: I want to travel from 12/29 to 12/31.

ASSISTANT: Do you have any specifications?

USER: I need a connecting flight.

ASSISTANT: Ok, please wait a moment, I will search a flight for you.

USER: Sure.

ASSISTANT: Sorry, there were no flights found on your route.

USER: Its ok, thank you.

ASSISTANT: Thank you for reaching us.