You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I abet you?

USER: I am Dorothy White, I would like to give a surprise party at Phoenix, to make the arrangement I need to book a flight ticket to AZ-PHX to CO-DEN.

ASSISTANT: Sure, we are ravish to help you. May I know your price limit?

USER: Thank you. I can afford up to 500.

ASSISTANT: Please share me your trip dates?

USER: My trip dates will be 12/18 to 12/20.

ASSISTANT: Thanks for waiting, there are no flights available at this moment matching your particulars.

USER: That's ok, thank you for your effort.

ASSISTANT: Thank you for choosing us.