You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: I am planning to book a ticket from PHL to DEN. Can you please help me out to book a ticket for me?

ASSISTANT: Can you please let me know your connection limit?

USER: I am looking for a direct flight.

ASSISTANT: May I know your planned journey dates?

USER: I would like to travel on June 13 and return back on June 15.

ASSISTANT: Do you have any other preference?

USER: No.

ASSISTANT: Can I know your name?

USER: My name is Gregory Moore.

ASSISTANT: Sorry, no flights available on your route.

USER: That's fine, thank you for your service.

ASSISTANT: Thank you for reaching us.