You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I aid you?

USER: Please help me to book a flight ticket from PHL to SFO.

ASSISTANT: Sure, I am here to help you, Please let me know your travelling dates.

USER: My travelling dates are from Dec, 06 to Dec, 08.

ASSISTANT: Do you have any break in between journey?

USER: I need a direct flight to fly.

ASSISTANT: Is there any other specifications for you?

USER: No.

ASSISTANT: May I know your good name?

USER: Donald Hill.

ASSISTANT: Sorry, no flights are available on your journey routes.

USER: Thank you for your information.

ASSISTANT: Thank you for contacting us.