You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you today?

USER: Could you please book a flight ticket from JFK to DEN?

ASSISTANT: Sure, may I know your trip dates?

USER: My trip dates are Aug 02 and Aug 04.

ASSISTANT: Do you have any class preference?

USER: I prefer an economy class.

ASSISTANT: Are there any other specifications?

USER: I prefer a normal cost airline.

ASSISTANT: Can I have your good name?

USER: I am Frank Anderson.

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

USER: Not a problem, thank you for the information.

ASSISTANT: Thank you for reaching us.