.black_layer{ width:100%; height:100%; background:#000; position:absolute;
z-index:99; top:0; left:0px; opacity:0.5;-khtml-opacity:0.5;-moz-opacity:
0.5;
filter: progid: DXImageTransform.Microsoft.Alpha( opacity=50 ); /* IE6,
IE7, and IE8 */
-ms-filter : "progid:DXImageTransform.Microsoft.Alpha( opacity=50 )"; /*
IE8 only */}
浮层
原文：http://www.cnblogs.com/rainbow661314/p/3544517.html
