You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Could you help me in booking a flight ticket from DTW to ORD?

ASSISTANT: Yes sure, Can I know your trip dates?

USER: And, my travelling dates are 11/06 to 11/08.

ASSISTANT: Give me a minute.

USER: OK,sure.

ASSISTANT: Can I know your name?

USER: Yes, I am Justin Clark.

ASSISTANT: Sorry Mr. Clark. No flight is there.

USER: OK,thank you.