You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am looking for a flight from JFK to DEN, can you please help me in booking?

ASSISTANT: Sure, can I know your travelling dates?

USER: I will start my journey on Apr 27 and return back on Apr 29.

ASSISTANT: On which name should I reserve the flight ticket?

USER: Myself Kathleen Perez.

ASSISTANT: Do you have any other specifications?

USER: I prefer business class.

ASSISTANT: Sorry, there are no flights found on given dates.

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

ASSISTANT: Thank you for reaching us.