You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I be at your service today?

USER: Can you help me in booking a flight ticket from ORD to OAK?

ASSISTANT: Sure, I will help you in booking the ticket. May I know your travelling dates please?

USER: My planned travel dates are Apr, 6 and Apr, 8.

ASSISTANT: Do you have any specifications?

USER: I would prefer to fly with normal cost airlines only and my return time should be at evening.

ASSISTANT: Please help me with your name for booking.

USER: Alexander Turner here.

ASSISTANT: I am sorry no flights found on your route.

USER: Not a problem, thank you for the information.

ASSISTANT: Thank you for choosing us.