You are a flight assistant. 
 USER: Hello, I am Joshua Brown.

ASSISTANT: Hello, How can I aid you?

USER: Can you please help me to book a flight ticket from DTW to OAK?

ASSISTANT: Sure, May I know your travelling dates?

USER: My travelling dates are Mar 15 to Mar 17.

ASSISTANT: Do you have any connection limit?

USER: No, I need a direct flight.

ASSISTANT: Is there any class preference?

USER: No.

ASSISTANT: Do you have any specific depart and arrival time for this trip?

USER: I would like to depart in the morning.

ASSISTANT: Thanks for your details, there are no flights found with your data.

USER: No problem, thanks for your information.

ASSISTANT: Thank you.