You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello. How can I assist you for the day?

USER: I am Virginia Lopez. Can you help me in booking a flight ticket from DEN to OAK?

ASSISTANT: Sure, I am here to help you with that flight ticket booking. May I know your travelling dates, please?

USER: I want to travel on 02/18, and return on 02/20.

ASSISTANT: Do you have any airline preference?

USER: No.

ASSISTANT: May I know your connection limit?

USER: I need a single connection.

ASSISTANT: Do you have any particular time for departing and returning?

USER: I want to return in the afternoon time.

ASSISTANT: Sorry to inform you that, there are no flights found on this route as per your travel dates.

USER: Ok, no problem. Thanks for the information.

ASSISTANT: Thank you for reaching us, have a great day.