You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: I am Christopher Miller. I want to book a ticket from DFW to LAS, can you please make a reservation?

ASSISTANT: Sure, may I know your planned travel dates?

USER: My travelling dates are on Nov 16 and Nov 18.

ASSISTANT: Do you have any specifications?

USER: My depart time is evening.

ASSISTANT: Please share me your connection limit.

USER: My connection limit is 1.

ASSISTANT: Is there any class preference for you?

USER: No.

ASSISTANT: Please wait for a moment.

USER: Sure.

ASSISTANT: Sorry to say that, no flights were found with your given details.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for reaching us.