You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you today?

USER: I am looking to book a flight ticket to meet my friend in San Francisco. Can you help me for booking a flight ticket from DEN to SFO?

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

USER: My travelling dates are Mar 04 and Mar 06.

ASSISTANT: May I know your connection limit?

USER: I need a single connecting flight.

ASSISTANT: Do you have any other requirements?

USER: I prefer to book a business class.

ASSISTANT: Ok, please wait for a moment.

USER: Sure, I will wait for your response.

ASSISTANT: May I know your name please?

USER: My name is Raymond Taylor.

ASSISTANT: Sorry, there are no flights found with your given details.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you for choosing us.

USER: Welcome.