You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

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

ASSISTANT: Can I know your desired travel dates please?

USER: Sure, I would like to take off on May 21st and return on May 23rd.

ASSISTANT: Do you have any class preference?

USER: Yes, I prefer economy class.

ASSISTANT: Sorry to say, there is no flight on your desired travel dates.

USER: Ok, no issues. Thank you for checking.

ASSISTANT: Thank you for contacting us.

USER: You are welcome.