You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I am planning to attend music concert at HOU, can you please help me with booking a flight ticket from DTW?

ASSISTANT: Sure, I am happy to help you. Could you please let me know your travel dates?

USER: Sure, I would like to take off on Oct 1 and return on Oct 3.

ASSISTANT: Ok, please provide me your class preference.

USER: I would prefer economy class.

ASSISTANT: Ok, is there any other requirements?

USER: I am looking for a direct flight.

ASSISTANT: May I know your name?

USER: Michael Lee.

ASSISTANT: Thank you. Please wait for a while.

USER: Ok, take your time.

ASSISTANT: Sorry to tell you that there is no flight available as per your requirements.

USER: That's ok. Anyways, thank you for your help.

ASSISTANT: You are welcome and thank you for choosing us.