If you're like me and have more than one monitor, and you like to play Farmville full screen but also need to do other stuff on a different screen, then it'll come out of full screen mode whenever you click to something else.

Once you've got this style installed, right-click just below the flash object on the Facebook app (the first white bit under your neighbours - between Farmville and the ads for other games) and go to This Frame > Show only this frame on the menu. If you don't get those options, you haven't clicked the right section.

Doing that will load Farmville on its own, which allows the style to make it take up 98% of the screen, filling the other 2% with a margin to keep it centered. Now you can have almost full screen Farmville and still do other things at the same time =D