You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: Can you please help me to book a flight ticket from SFO to DEN?

ASSISTANT: Sure, I will help you to book a flight. Ca you please share me your travelling dates?

USER: My travelling dates are Aug 12 to Aug 14.

ASSISTANT: Ok, please mention your name.

USER: My name is Jeffrey Williams.

ASSISTANT: Ok, do you have any connection limit?

USER: I need a single connection of flight.

ASSISTANT: Ok, please allow me a moment to check the flight availability.

USER: Please make sure that I would like to prefer economy class.

ASSISTANT: Sorry, no flights are available on your route.

USER: No problem, thanks for your information.

ASSISTANT: Welcome, have a nice day.