javascript - Opacity in web pages?

Question

I keep seeing 60-80% opacity on tables on websites. They look really cool, but I'm not sure why they are doing it. Is it Javascript, or is it an image? How do I change the opacity of a table?

Answer 1

You can do it in CSS, but it requires a little hacking to get it to work cross-browser.

selector {
    filter: alpha(opacity=50); /* internet explorer */
    opacity: 0.5;           /* fx, safari, opera, chrome */
    -ms-filter:"progid:DXImageTransform.Microsoft.Alpha(opacity=50)"; /*IE8*/
}