You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am David Lewis.

ASSISTANT: David Lewis, how may I assist you today?

USER: Can you help me in booking from JFK to DEN, as there is a conference meeting to attend?

ASSISTANT: Yes, I will help you. May I know with your planned travel dates please?

USER: My trip dates are Sep 21 to Sep 23.

ASSISTANT: Thank you.

USER: Ok.

ASSISTANT: Do you need a direct or connecting flight?

USER: I need a connecting flight.

ASSISTANT: May I know with your class preferences please?

USER: I don't have any preferences.

ASSISTANT: Please let me know if you have any other preferences in your flight journey.

USER: I just need a connecting flight.

ASSISTANT: I am sorry to inform you that there are no connecting flights available.

USER: No issue, thank you.

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