How can check invisible nick Yahoo?

Question

I don't know how to check invisible nick Yahoo Messenger. I checked only online or offline by link :http://opi.yahoo.com/online?

Now some sites can check invisible and get status :
http://yahootracer.com/
http://invisible.yahooscan.eu/
http://www.statusdetect.com/
http://www.persiangap.com/
How can use these sites to get result in application.
Thanks!