You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you?

USER: I am Brandon Williams. I planned to meet my friend in PHL, can you please help me to book a flight ticket from DEN?

ASSISTANT: Fine, please mention your trip dates so that I can help you in a better way.

USER: I prefer to travel on 03/18 and 03/20.

ASSISTANT: Wait a moment, I will check for the flight on your route.

USER: I need a direct flight.

ASSISTANT: Sorry to say, there is no direct flight available on your route.

USER: Ok, no problem. Thank you for your time.

ASSISTANT: Welcome, have a good day.