You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Michael Smith here.

ASSISTANT: How can I help you?

USER: Can you please reserve me a flight ticket from DFW to DTW?

ASSISTANT: Let me know your travelling dates.

USER: Sure, my travel dates are from Nov 14 to Nov 16.

ASSISTANT: Do you have any preference?

USER: I would like to return in the evening.

ASSISTANT: Sorry, no flights found for your travelling dates.

USER: Ok, no problem. Thank you for the information.

ASSISTANT: Thank you.