body{ background: red; opacity: 0.5; filter:alpha(opacity=50); }
jQuery：
if($.support.opacity == ture){ $(‘body‘).css(‘opacity‘,0.5); }else{ $(‘body‘).css(‘filter‘,‘alpha(opacity=50)‘); }
在IE中opacity透明度
原文：http://www.cnblogs.com/by-dxm/p/6394677.html
