You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you?

USER: Can you book a ticket from PHL to DFW? As I'm planning to go for a small tour.

ASSISTANT: Sure, I am happy to help you and can you please mention your preferable travel dates that you have planned?

USER: Sure, my planned departure and return travel dates are 13th and 15th of August.

ASSISTANT: Do you need a direct or connecting flight?

USER: I'm ok with both of them.

ASSISTANT: Is there any time preferences that you have?

USER: Yes, I want to return in the evening time.

ASSISTANT: May I know your name please?

USER: Yes, my name is Dennis Wright.

ASSISTANT: Thank you for your information, I regret to inform you that there is no flight obtained on your journey dates to book a flight ticket.

USER: That's ok, thank you for giving the information anyways.

ASSISTANT: You are most welcome and thank you for reaching us.