You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I guide you for today?

USER: I am Richard Wright. I would like to reserve a flight ticket from San Francisco, can you please find a direct flight for me?

ASSISTANT: Can you please share on what dates you are willing to travel?

USER: Thank you for considering my request. I am willing to travel on the dates of Jan 11 and Jan 13.

ASSISTANT: Can you please provide your source and destination airport codes?

USER: The origin and destination airport codes are SFO and PHL.

ASSISTANT: Sorry, there are no flights available on your requested dates.

USER: It's ok, not a problem with that. Thank you for your time.

ASSISTANT: Thank you for contacting us, have a nice day.

USER: Most welcome.