You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: Can you please help me in booking a flight ticket from Washington, IAD to Denver, DEN?

ASSISTANT: Sure, let me know your travelling dates.

USER: My journey dates are from Oct 04 to Oct 06.

ASSISTANT: May I know your connection limit?

USER: I need a connecting flight.

ASSISTANT: Do you have any other requirements?

USER: Yes, I want to return in the evening flight.

ASSISTANT: May I know your name please?

USER: My name is Christopher Young.

ASSISTANT: Sorry, there are no flights found with your given details.

USER: Ok, not an issue. Thank you.

ASSISTANT: Thank you opting us.