my macbook pro's battery status is 99% and it keep saing the battery is charged. what should i do? tanks

No need to do anything, as your battery and computer are operating as designed. See below for details.

http://support.apple.com/kb/TS1909

Do nothing. This is a correct indication.

That is normal.

If the battery icon in the Finder menu bar is set to show the percentage of charge , you might sometimes notice that the battery does not attain a full 100 percent charge when the power adapter is attached. This is normal behavior; battery life is maximized if charging is not continuously cycled on and off when the battery’s charge capacity is between 95 and 100 percent. When the battery level eventually drops below 95 percent, it will charge all the way to 100 percent.
http://manuals.info.apple.com/en_US/MacBook_Pro_Users_Guide.pdf

Best.

Nothing! When the battery has been fully charged and the MBP is connected to a wall outlet, the battery will not be used and will slowly lose its charge. When it drops to about 95%, then the battery will be charged again to 100% and the start the cycle again. You may relax.

ciao.

You're welcome.