You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I aid you now?

USER: Please book a flight ticket from SFO to DEN.

ASSISTANT: Yes, I will definitely try my best to help you in booking your flight ticket. Could you please provide your planned dates of journey?

USER: My trip dates are 07/18 and 07/20.

ASSISTANT: Do you have any limit on number of connections for your journey?

USER: I am comfortable to travel in a single connecting flight.

ASSISTANT: May I know your other specifications for the journey?

USER: I prefer to travel with the comforts of business class.

ASSISTANT: Let me know your good name for documentation purpose.

USER: Margaret Lopez here.

ASSISTANT: Sorry to say that, we have not found any flights running on your desired routes.

USER: That's ok, thank you for your information.

ASSISTANT: Thank you for reaching us, have a nice day.