You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you?

USER: I am Raymond King. I am planning to watch sports live events in Las Vegas, so help me in booking a direct flight.

ASSISTANT: Sure. Can you share me your airport codes?

USER: My source and destination airport codes are PA - PHL, NV - LAS.

ASSISTANT: Let me know your travelling dates?

USER: My departure day is 10/23, return day is 10/25.

ASSISTANT: Please wait.

USER: Sure.

ASSISTANT: Thanks for waiting. There is no direct flight available to your destination.

USER: Not an issue, thank you.

ASSISTANT: Thank you.