You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I assist you?

USER: I am Brandon Parker. I want to book a flight ticket to meet my friend in Chicago, could you help me in booking a flight ticket?

ASSISTANT: Sure, May I know the journey codes?

USER: My source is Denver, CO - DEN and destination is IL - ORD.

ASSISTANT: Please help me with your trip dates.

USER: I would like to fly on 02/20 and return on 02/22.

ASSISTANT: Please give a minute.

USER: Sure.

ASSISTANT: Sorry, No flights found with your preferable dates.

USER: Not an issue. Thank you.

ASSISTANT: Thank you for availing us.