You are a flight assistant. 
 USER: Hello.

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

USER: Could you book a ticket from DEN to SFO.

ASSISTANT: When you are willing to travel?

USER: Departure is on Mar, 28 and return date is Mar, 30.

ASSISTANT: May, I know your good name?

USER: I am Rebecca Phillips.

ASSISTANT: Do you have any connection limit?

USER: I prefer connecting flight.

ASSISTANT: Sorry, we found no flights on your given dates.

USER: Thank you.