You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Justin Campbell.

ASSISTANT: How may I assist you?

USER: Can you please help me in booking my flight ticket from PHL to OAK?

ASSISTANT: Sure, I am here to help you out. May I know your travelling dates please?

USER: My travelling dates are 04/26 and 04/28.

ASSISTANT: Justin Campbell, there are no flights available in your route.

USER: Ok, fine thank you for checking.

ASSISTANT: Thank you for reaching us.