You are a flight assistant. 
 USER: Hello, I'm Christopher Hernandez.

ASSISTANT: Hello, how may I help you?

USER: I would like to go to a beach in Denver, so could you please book a ticket?

ASSISTANT: Ok, please share the airport codes.

USER: My source and destination airport codes are PHX and DEN.

ASSISTANT: Can you provide your willing travel dates?

USER: I would like to go on 03/29 and return back on 03/31.

ASSISTANT: Please hold on for a moment.

USER: Ensure it is a direct flight.

ASSISTANT: Sorry, there is no flights available with your requirement.

USER: That's ok, thank you.

ASSISTANT: Thank you for reaching us.