You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you now?

USER: I want to book a flight ticket from JFK to DEN, can you please help me with this?

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

USER: My travelling dates are Nov 26 to Nov 28.

ASSISTANT: Are you ok with connecting flight?

USER: Yes, I am ok with connecting flight.

ASSISTANT: Any more specifications do you have?

USER: I want to return in the afternoon.

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

USER: Melissa Brown here.

ASSISTANT: Please wait a moment to check the flights.

USER: Sure.

ASSISTANT: Unfortunately there are no flights running on your route with your required preferences.

USER: No problem, thanks for your information.

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