How to find if someone is invisible or online or offline in Yahoo.

So here is simple way to find out who is invisible/offline/online in yahoo.
Just paste the following code in address bar & follow the steps & see the status.
http://opi.yahoo.com/online?u=insert Yahoo ID&m =g&t=2
replace the "insert Yahoo ID" with the yahoo email id of the person and open this whole address into the address bar and hit enter ,
eg: let id is crypto@yahoo.com then the url must be like this:
http://opi.yahoo.com/online?u=crypto@yahoo.com ID&m =g&t=2
u can search for all ur friends, whether they are online or offline.
Note: m can has values g or t, t stands for text and g for graphics whereas t can be 1, 2 or 3 for size of text or graphic....