CSS transparent code compatible with mainstream browsers

Transparency tends to produce good web visuals. The following are CSS transparent code compatible with mainstream browsers.
Transparent_class {

Filter:alpha (OPACITY=50);

-moz-opacity:0.5;

-khtml-opacity:0.5;

opacity:0.5;

}

Filter:alpha (OPACITY=50): This is set for IE6, the value is 0-100, the other three 0 to 1.
-moz-opacity:0.5; This is to support some of the older versions of Mozilla browser.
-khtml-opacity:0.5; This is to support some of the older versions of the Safari browser.
opacity:0.5; This is the most important because it is a CSS standard. This property supports Firefox, Safari, and Opera.