You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Barbara Lopez.

ASSISTANT: Barbara Lopez. How can I help you?

USER: I am planning to book a ticket from IAD to DEN. Can you please share your preferable journey dates?

ASSISTANT: May I have your travel dates please?

USER: I am planning to travel on Mar 02 and return back on Mar 04.

ASSISTANT: Do you have any airline preferences?

USER: No, I am looking for a business class.

ASSISTANT: Is there any time concern?

USER: Yes, my return time is morning.

ASSISTANT: Let me know the connection limit?

USER: I am ok with any connection.

ASSISTANT: Are there any other requirements, you want to avail?

USER: No.

ASSISTANT: Give me a moment.

USER: Sure.

ASSISTANT: I regret to inform that there are no flights available according to your preferences?

USER: That's fine, thank you for your service.

ASSISTANT: Thank you for reaching us.