You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Stephen Miller.

ASSISTANT: What can I do for you today?

USER: I would like to book a flight ticket from Washington DC-DCA, can you please help me in booking a ticket to Denver CO-DEN?

ASSISTANT: Sure. When will be your trip dates?

USER: My trip dates are 01/03 and 01/05.

ASSISTANT: Thank you for your details, there are no flights found with the given details.

USER: Ok, not an issue. Thank you.