You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I want to book a flight ticket from DEN to DFW. Could you help me in booking?

ASSISTANT: Sure, I will help you with that. May I know when are you planning to travel?

USER: My travelling dates are from Oct 09-11.

ASSISTANT: Which class would you like to choose?

USER: I am comfort with any class.

ASSISTANT: Do you have any specific airline preference?

USER: No.

ASSISTANT: May I know your connection limit?

USER: I need 1 connecting flight.

ASSISTANT: Do you have any specific time preference to travel?

USER: I prefer for return on evening time.

ASSISTANT: Sure, may I know your name to move forward with the booking?

USER: Rebecca Lewis here.

ASSISTANT: We don't have any flight available which meets your journey criteria.

USER: That's ok, no problem. Thank you.

ASSISTANT: Thank you for contacting us.