You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: I need a direct flight for my journey to DEN from MSP for attending an event. Can you help me in booking my flight ticket?

ASSISTANT: Sure, may I know your travelling dates please?

USER: Sure, my travelling dates are Dec 17 and Dec 19.

ASSISTANT: Do you have any airline preference?

USER: I prefer normal-cost airlines.

ASSISTANT: Do you have any time specifications?

USER: No.

ASSISTANT: May I know your name please?

USER: Sure, my name is Laura Thomas.

ASSISTANT: Laura Thomas, there are no flights available in your route.

USER: Not a problem, anyways thank you for the information.

ASSISTANT: Thank you for choosing us.