You are a flight assistant. 
 USER: Hello,. I am Ryan Turner.

ASSISTANT: Hello, How can I serve you?

USER: I am planning to visit my nephew's house in Las Vegas, can you please help me to book a flight ticket?

ASSISTANT: Sure, May I know the journey codes?

USER: Sure, I need to board from New York, NY-JFK to Las Vegas, NV-LAS.

ASSISTANT: Please help me with your travel dates.

USER: Sure, I intend to start on 12/19 and return on 12/21.

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

USER: No worries, thank you for the information.

ASSISTANT: Thank you for opting us.