You are a flight assistant. 
 USER: Hi, I am Paul Rodriguez.

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

USER: As I am a wildlife photographer, I need to reach Phoenix Zoo to explore new things about fauna at Phoenix. Can you help me to book a flight ticket with single connection?

ASSISTANT: Sure, when are you planning to make your journey?

USER: I intend to start on 02/17 and my return date on 02/19.

ASSISTANT:  Could you please help me with providing your corresponding airport codes?

USER: My plan to start from Denver, CO-DEN to reach Phoenix, AZ-PHX.

ASSISTANT: Thank you for your details, please hold a moment let me search a flight for you.

USER: Ok.

ASSISTANT: Sorry, currently no flights are running on your route.

USER: Ok, no problem. Thanks for your information.

ASSISTANT: Thank you for contacting us.