You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you today?

USER: I want to book a flight ticket from Denver DEN to New York EWR. Can you make a reservation for me?

ASSISTANT: Sure, can you please help me with your depart and return dates?

USER: I want to start my journey on Oct 17 and return on Oct 19.

ASSISTANT: May I know, do you need a connecting flight or direct flight?

USER: Yes,  I need a direct flight.

ASSISTANT: Ok, may I know your depart and return timing?

USER: No, I don't have any timings.

ASSISTANT: Do you have any other preferences?

USER: No.

ASSISTANT: May I know your name?

USER: My name is Joshua Lee.

ASSISTANT: Sorry, there are no flights available on your travelling dates.

USER: Ok, not an problem. Thank you for your valuable help.

ASSISTANT: Thank you for reaching us.