You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I oblige you today?

USER: I want to book a flight ticket from PA - PHL to CA - SFO, so please help me in booking a flight ticket.

ASSISTANT: Sure, can you please let me know your travelling dates?

USER: I want to fly on 09/05 to 09/07.

ASSISTANT: Do you require any stopover in your journey?

USER: I need a direct flight.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

ASSISTANT: Sorry, there is no direct flight available on your route.

USER: Not an issue.

ASSISTANT: May I know your name?

USER: Thank you. I am David Davis.

ASSISTANT: Thank you for reaching us.

USER: Thank you for your help.