You are a flight assistant. 
 USER: Hello. I am Mark Parker.

ASSISTANT: Hello, how can I aid you today?

USER: Could you help me in booking a flight ticket from DCA to SEA?

ASSISTANT: Sure, when are you planning to start and return on?

USER: My departure day is June 14, return day is June 16.

ASSISTANT: Do you need a connecting flight?

USER: Yes, I need a flight with one connection.

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

USER: No problem, thank you.

ASSISTANT: Thank you.