body {
background-image:url('fundo2.jpg');
background-repeat:no-repeat;
background-attachment:fixed;
background-position:50% 50%; 
background-size:100% 100%;
-webkit-background-size: 100% 100%;
-o-background-size: 100% 100%;
-khtml-background-size: 100% 100%;
-moz-background-size: 100% 100%;

}