You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: Can you aid me to book my ticket from DEN to SFO?

ASSISTANT: Sure, may I know the travelling dates?

USER: My trip dates are June 14 and June 16 respectively.

ASSISTANT: Do you have any connection limit?

USER: I am comfortable with any flight.

ASSISTANT: Are there any other requirements?

USER: No other preferences for me.

ASSISTANT: May I know your name?

USER: Ronald Garcia here.

ASSISTANT: Please wait a minute.

USER: Ok.

ASSISTANT: Sorry, no flights found with your chosen dates.

USER: Thank you.

ASSISTANT: Thank you for opting us.