You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: Can you help me booking a flight ticket from PHL to SFO?

ASSISTANT: Sure, please provide your trip dates.

USER: I will start on 07/28 and return on 07/30.

ASSISTANT: Do you prefer a direct or connecting flight?

USER: I need a break in my journey.

ASSISTANT: Do you prefer economy or business class?

USER: I am comfortable with any flight.

ASSISTANT: May I know your name?

USER: I am Donna Nelson.

ASSISTANT: Sorry Donna Nelson, no flights are available on your route.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for reaching us.