You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: This is Anthony Moore, can you help me to book a flight ticket from DTW to IAH?

ASSISTANT: Sure, please provide your trip dates.

USER: My preferable journey dates are Mar 09 and Mar 11.

ASSISTANT: Do you have any other requirements?

USER: I would like to return back in the afternoon time.

ASSISTANT: Ok, please wait a minute.

USER: Sure.

ASSISTANT: Sorry Anthony, we regret to inform you that there is no flight available as per your request.

USER: No problem, thank you for the information.

ASSISTANT: Most welcome.