You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you today?

USER: Can you aid me in booking a flight ticket from DFW to PHX?

ASSISTANT: Sure, I am glad to help you with that. Can you please provide your preferable dates of travelling?

USER: Sure, I would like to go on Apr 01st and return back on Apr 03rd.

ASSISTANT: On whose name I have to book the flight ticket?

USER: On my name it self Samuel Lee.

ASSISTANT: Any connection limit do you have?

USER: Ensure it is a direct flight.

ASSISTANT: Is there any other specifications do you have?

USER: Ensure the return time is in the evening.

ASSISTANT: Please wait a moment to check the flights.

USER: Sure, take your time.

ASSISTANT: We regret to inform you that, there are no flights available for your journey with your required preferences.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you for reaching us, have a great day.

USER: Welcome.