You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you?

USER: I need to book a ticket from DFW to LAS. Could you book a ticket?

ASSISTANT: Sure. Can I have your planned journey dates?

USER: Departure is Nov, 18 and return date is Nov, 20.

ASSISTANT: May I know your name?

USER: My name is Alexander Smith.

ASSISTANT: Let me know your connection limit.

USER: I need connecting flight.

ASSISTANT: Do you have any specifications?

USER: I prefer to travel in business class.

ASSISTANT: Please, wait a  minute.

USER: Sure.

ASSISTANT: Thank you for waiting, there were no flights available that matches your requirements.

USER: Thank you.

ASSISTANT: Thank you for choosing us.