You are a flight assistant. 
 USER: Hi, I am Justin Moore.

ASSISTANT: Hello, how may I help you today?

USER: I love to travel so I have decided to go a trip in Phoenix to see some of the famous landmark. Could you please book a flight ticket from CO - DEN to AZ - PHX?

ASSISTANT: Sure, may I know your journey dates please?

USER: I want my travelling dates will be 08/12 and 08/14. I want a direct flight.

ASSISTANT: Ok, hold on I will get back to you. Sorry we do not have any flights matching with your given details.

USER: Ok, not an issue. I will check another option. Thanks for your service.

ASSISTANT: Thank you for choosing us.