CSS3 - transparent baggrund

CSS kode 

 img
  {
  opacity:0.5;
  filter:alpha(opacity=40); /* For IE8 and earlier */
  }

CSS kode 

 .forside {
     background-image: url("http://localhost:8080/faeroeerne/images/lilledimon1.png");
     background-repeat: no-repeat;
     background-size: 630px 500px;
 }

CSS kode 

 .alpha60 { 
 /* Fallback for web browsers that doesn't support RGBa */ 
 background: rgb(0, 0, 0) transparent; 
 /* RGBa with 0.6 opacity */ 
 background: rgba(0, 0, 0, 0.6); 
 /* For IE 5.5 - 7*/ 
 filter:progid:DXImageTransform.Microsoft.gradient(startColorstr=#99000000, endColorstr=#99000000); 
 /* For IE 8*/ 
 -ms-filter: "progid:DXImageTransform.Microsoft.gradient(startColorstr=#99000000, endColorstr=#99000000)"; 
 }