You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you at this moment?

USER: Can you aid me to book my ticket from DEN to JFK?

ASSISTANT: Sure, I will help you with that. Can you please mention your preferable travel dates?

USER: My trip dates are Jan 26 and Jan 28 respectively.

ASSISTANT: May I know your name for further process?

USER: Alexander Lewis here.

ASSISTANT: Do you have any another specifications?

USER: I prefer for connecting flight and business class flight to travel.

ASSISTANT: Sorry, no flights are available in this route as per your requested dates.

USER: Thank you for the help.

ASSISTANT: Thank you for reaching us.