You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you at this moment?

USER: I need your help to find a flight from DFW to LAS. Can you please do that for me?

ASSISTANT: Sure, can I have your  travel  dates please?

USER: Thank you. I am planning to travel on the dates of Dec 18 and Dec 20.

ASSISTANT: Do you prefer any specific airlines to travel?

USER: No but I am looking for a business class flight.

ASSISTANT: Do you  have any other specifications?

USER: I need a single connected flight for my journey.

ASSISTANT: Can I have your good name please?

USER: My name is Jacob Jackson.

ASSISTANT: Sorry to inform you that no flight is available to you  with business class on your  planned dates.

USER: It's ok, not a problem with that. Thank you for your time.

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