You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you?

USER: I would like to visit Phoenix, could you please help me to book my flight ticket from DEN to PHX?

ASSISTANT: Sure, let me know your travel dates please?

USER: I would like to depart on Mar 10th and return back on Mar 12th.

ASSISTANT: May I know your connection limit?

USER: I would like to prefer for a connecting flight.

ASSISTANT: Do you need any other preference?

USER: I prefer for an economy class.

ASSISTANT: Can I know your name please?

USER: Myself Dorothy Turner.

ASSISTANT: Sorry to inform you that there are no flight services available on your given dates.

USER: No problem, thank you for checking.

ASSISTANT: Thank you for reaching us.