You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you today?

USER: I am Betty White. Can you please help me to find a business class flight from Oakland to Dallas?

ASSISTANT: Sure, I am happy to help you with that.

USER: Thank you for accepting my request.

ASSISTANT: Can I have your travel dates please?

USER: My travel dates are Jan 3rd and Jan 5th.

ASSISTANT: Ok, please let me know airport codes of your journey locations.

USER: The source and destination airport codes are OAK and DFW.

ASSISTANT: Do you have any other specifications?

USER: Ok, I need a flight which is returning in the evening time.

ASSISTANT: Sorry Betty White, no flight is available to you on your dates due to some issues.

USER: It's ok, not an issue with that. Anyways thank you for your time.

ASSISTANT: Thank you for choosing us, have a good day.

USER: You are most welcome.