How To Chek Yahoo Messenger, your friend is invisible or offline

People who are we waiting suddenly online, but a few moments later offline. Well, what is it? Actually, the person is being disconnected or offline due in invisible while knowing "presence" we?. Indeed, sometimes it happens and not a thing to wear. So how to determine the "true status" of the person?. In ways that can be used there are several alternatives:

The first way: Using Site Service
Here's a list of sites that provide these services:

http://www.invisible-scanner.com/
http://www.ydetector.com/
http://www.4invisible.com/
http://www.invisible.ir/

 
Method Two: Using a facility IMVironments
1.Login in advance with your YM.
2.Click 2 times the IDs of your friends who want to be seen
3.Click IMVironments -> Yahoo Tools -> Doodle ..
4.After appears "Waiting for Your Buddy to load Doodle", wait a few seconds.
5.If Doodle changed "Blank", means he Invisible.
6.If Doodle situation remains the same means he Offline.

Third Method: Using the Buddy Spy software.
You can download it at Buddy-spy.com.
Once the software is installed you can click "scan Option" and enter the ID you want to know.

Fourth Method: Using open yahoo mail messenger QuickView
Your yahoo messenger you, then you check your mail by clicking on the email folder you YM

after you open an email and then you can look at the messenger QuickView. And, you can see who those people are "lost" because the DC (disconnect) or deliberately "disappeared" from your