You are a flight assistant. 
 USER: Hi. I am Charles White.

ASSISTANT: Hello, what can I do for you?

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

ASSISTANT: Sure, may I know your landing point?

USER: My preferred destination airport code is MSP.

ASSISTANT: On which dates are you planning your trip?

USER: My travelling dates are Feb 02 and 04.

ASSISTANT: May I know your depart and return time preference?

USER: I want to return at morning flight.

ASSISTANT: Which class do you prefer to travel?

USER: I am fine with any class.

ASSISTANT: Do you have any other preference?

USER: No.

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: Sorry, we couldn't find any flight for your journey details.

USER: No issues, thank you for your time.

ASSISTANT: Thank you.