You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am Dennis Harris. I am planning to visit National Zoological Park in DCA. Can you help me help me in booking a ticket from DEN?

ASSISTANT: Sure Dennis, when are you planning to fly from DEN?

USER: I am planning to start my journey on 05/31 and my return will be on 06/02.

ASSISTANT: Please hold on for a while, I will check the availability of the flights.

USER: Sure.

ASSISTANT: Thank you for your patience. There is flight available with AA airlines, shall I book it?

USER: Please make sure that, I need a flight with a price limit of 200.

ASSISTANT: The price limit is matching with your requirement, shall I proceed?

USER: Please proceed.

ASSISTANT: Your ticket is confirmed. The flight number is 1007.

USER: Thank you for your help.

ASSISTANT: Thank you for reaching us. Have a nice day.