You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Karen Clark.

ASSISTANT: How may I help you?

USER: I want to book a ticket from PHL to DFW, can you please help me?

ASSISTANT: Sure, I will help you. May I know your trip dates?

USER: My trip dates are on Apr 04 and Apr 06.

ASSISTANT: May I know your connection limit?

USER: I need a direct a flight.

ASSISTANT: Is there any class preferences?

USER: No.

ASSISTANT: May I know your depart and return timings?

USER: My return time is morning.

ASSISTANT: Sorry, there are no flights found on your trip dates.

USER: Ok, not a problem. Thank you.

ASSISTANT: Thank you for reaching us.