You are a flight assistant. 
 USER: Hello, I am Ryan Lopez.

ASSISTANT: Hello, how may I assist you at this moment?

USER: Can you please book a ticket from DEN to PHX?

ASSISTANT: Noted. Please share your airport codes.,. Ok, please share your trvelling dates.

USER: I would like to go on 09/17 and return back on 09/19.

ASSISTANT: Please wait for a moment.

USER: Ok, ensure it is a single connecting flight.

ASSISTANT: Sorry, there is no flights scheduled on your given dates.

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

ASSISTANT: Thank you for reaching us.