Vertical Centering

chinese ver. http://www.blueidea.com/tech/site/2006/3804.asp
original ver. http://www.jakpsatweb.cz/css/css-vertical-center-solution.html

There is a very confusing problem that each method only adapt for specialized browser.

Relative 50% & -50% is not work well at FF 1.5 , seems that "relative -50%" property is not have any effect at FF 1.5 . This amazing me at first.