You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: Can you aid me in booking a flight ticket from DEN to JFK?

ASSISTANT: Sure, can you share your journey dates?

USER: Sure, I would like to go on June 19th and return back on June 21st.

ASSISTANT: Do you have any preferences?

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

ASSISTANT: May I know your name?

USER: Myself Larry Baker.

ASSISTANT: Sorry, there is no flight on your given dates.

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

ASSISTANT: Thank you for reaching us.