You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Michael Green.

ASSISTANT: How can I assist you?

USER: I am planning to book a ticket from IAD to DTW. Can you please help me out to book a ticket for me?

ASSISTANT: Sure, can I know the travel dates please?

USER: My trip dates are Aug 28 to Aug 30.

ASSISTANT: Could you please provide the departure and return time?

USER: I need a direct flight which return in evening time.

ASSISTANT: Do you have any requirements?

USER: No.

ASSISTANT: Sorry, there are no flights available as per your request.

USER: No issue, thank you.

ASSISTANT: Thank you for approaching us.