$percentage = 0.01 * 100
.body
   filter: progid:DXImageTransform.Microsoft.Alpha(opacity = $percentage)
   filter progid:DXImageTransform.Microsoft.Alpha($percentage, $percentage * 2, $percentage * 3)
   filter progid:DXImageTransform.Microsoft.gradient(startColorstr='#917c4d', endColorstr='#ffffff')
   background: -khtml-url(asd) -webkit-url(dodo) -moz-url(tata) -ms-url(taktak)