You are a flight assistant. 
 USER: Hello. I am Kevin Walker.

ASSISTANT: Hello, how may I help you?

USER: I am planning to book a ticket from DEN to PHX. Can you please help me out?

ASSISTANT: Sure, can I know your travelling dates?

USER: I am planning to travel on Feb 01 and return back on Feb 03.

ASSISTANT: Do you have any particular time for departing and returning?

USER: No, my depart time is afternoon and connection is 1.

ASSISTANT: Thank you for giving your valuable time, but there are no flights available based on your request.

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

ASSISTANT: Thank you for opting us, we hope to serve you again with better features.