You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, do you need any help from us?

USER: I am planning to visit Los Angeles, can you please book me a ticket from DEN to LAX?

ASSISTANT: Sure, could you please share your departure and arrival day?

USER: My preferable journey dates are Mar 04 and Mar 06.

ASSISTANT: Ok, could I have your name please?

USER: My name is David Lopez.

ASSISTANT: Ok, do you need direct or connecting flight?

USER: I prefer direct flight for this trip.

ASSISTANT: Ok, may I know your class preference?

USER: I am comfort any class.

ASSISTANT: Sorry, there is no flight with your requested connection limit.

USER: Ok, not an issue. Thank you for providing information.

ASSISTANT: You are welcome, have a great day.