You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: Can you please help me to book a flight ticket from IAH to DCA?

ASSISTANT: Sure, I am here to help you out. May I know your travelling dates please?

USER: My travelling dates are Feb 14 to Feb 16.

ASSISTANT: Can you please share your connection limit?

USER: I need a single connection of flight.

ASSISTANT: Is there any class preference?

USER: No.

ASSISTANT: May I know your name please?

USER: Nicholas Edwards.

ASSISTANT: Do you have any specifications?

USER: I prefer to fly in big brand airlines.

ASSISTANT: Nicholas Edwards,  there are no flights available in your route.

USER: No problem, thanks for your information.

ASSISTANT: Thank you for reaching us.