You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: I am Mary Gonzalez. I want to book a flight ticket from ORD to DTW. Could you help me in booking?

ASSISTANT: Sure, could you please provide your travelling dates?

USER: My travelling dates are from 12/13 to 12/15.

ASSISTANT: Please share your specifications.

USER: I need direct flight.

ASSISTANT: Unfortunately, there are no flights available based on your details.

USER: That's ok, no problem. Thank you.

ASSISTANT: Thank you for choosing us.