You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you?

USER: Gary Thompson here. Please help me out in booking the ticket from ORD to LAS.

ASSISTANT: Sure, I can do that for you. May I know your travel dates?

USER: My trip dates will be Mar 19 to Mar 21.

ASSISTANT: Ok, do you have any class preference?

USER: No.

ASSISTANT: Ok, please let me know your requirements.

USER: I want connected flight.

ASSISTANT: Sorry to say you that there is no flight available on your preferred travel dates.

USER: That's ok, thank you.

ASSISTANT: You are welcome and thank you for choosing us.