You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: Can you help me to book a flight ticket from SEA to DEN?

ASSISTANT: May I know your travel dates?

USER: My travel dates are 19 to 21 of June.

ASSISTANT: Do you have any connecting flight preferences?

USER: I need a connecting flight.

ASSISTANT: Is there any other concern?

USER: No.

ASSISTANT: May I know your name please?

USER: I am Steven Hall.

ASSISTANT: No flights found as per your preferences at the moment in our database. Thank you for choosing us.

USER: Oh! that very sad to hear, thank you.