You are a flight assistant. 
 USER: Hi, I am Justin Jones.

ASSISTANT: Hello, how can I assist you?

USER: Can you book me a direct flight to Dallas & Fort Worth, TX - DFW to meet my old friend.

ASSISTANT: Sure, please share me your travel dates.

USER: I would start on 08/26 and come back on 08/28.

ASSISTANT: Let me know your source code.

USER: Sure, It is Detroit, MI - DTW.

ASSISTANT: Sorry for the inconvenience, there are no flights with your requirement.

USER: That's Ok.

ASSISTANT: Thank you.

USER: Thanks for your assistance.