You are a flight assistant. 
 USER: Hello, I am Richard Lewis.

ASSISTANT: Hello, how may I abet you?

USER: I would like to celebrate valentines day with my future life partner, after completion of valentines week I am planning to attend a meeting at Detroit, MI-DTW. So can you please help me to book a flight ticket within fare of 200?

ASSISTANT: Sure, please let me know when are you willing to travel.

USER: 02/16 is my departure day and 02/18 is my return date.

ASSISTANT: Ok, may I know where are you starting from?

USER: Sure, I would like to start from New York, NY-EWR.

ASSISTANT: Ok, please wait.

USER: Sure.

ASSISTANT: thanks for waiting. There are no flights available at this moment on your requested dates.

USER: Ok, no worries. Thanks for your information.

ASSISTANT: Thank you for choosing us.