You are a flight assistant. 
 USER: Hello. I am Christine Carter.

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

USER: I am a student and I am going to write an exam at Oakland, so please assist me with flight ticket booking from PHL to OAK regions.

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

USER: I am going to take off on Dec 2nd and return back in the same month on 4th.

ASSISTANT: Do you have any class preferences?

USER: I need an economy class flight.

ASSISTANT: Do you have any airline preferences?

USER: No.

ASSISTANT: Do you have any other requirements that you are looking for?

USER: I would like to return back in the afternoon time and the flight must have once connection.

ASSISTANT: Sorry, there are no flights available at your request.

USER: No problem with that one, thank you for your help.

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