You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. Can you please tell me how may I help you?

USER: I would like to book a ticket from DTW to OAK, can you please help me out?

ASSISTANT: Sure, I can help you with the ticket booking. May I know your trip dates please?

USER: I am travelling on these dates Dec 17th and 19th.

ASSISTANT: What is your good name?

USER: Nicole Davis here.

ASSISTANT: Is there any preferences?

USER: I prefer normal-cost.

ASSISTANT: Ok, please wait a minute.

USER: I need single connected flight.

ASSISTANT: Sorry to inform you that, there are no flights available in the normal-cost airlines.

USER: Ok no problem, thank you for checking.

ASSISTANT: You are welcome. Thank you for reaching us.