You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you?

USER: I am Gregory Nelson.

ASSISTANT: Glad to meet you Nelson.

USER: I want to celebrate my grand father birthday at Oakland. Can you please help me with book a ticket from PHL - OAK?

ASSISTANT: Sure, may I know your journey dates please?

USER: My journey dates are 11/02 to 11/04.

ASSISTANT: Wait a moment please.

USER: Sure.

ASSISTANT:  Gregory Nelson, there are no flights available in your route.

USER: OK, no problem. Thanks for your information.

ASSISTANT: Thank you for approaching us.