.loader {

    position: fixed;

    left: 0px;

    top: 0px;

    width: 100%;

    height: 100%;

    z-index: 9999;

    background: url('../images/ruedas1.gif') 50% 50% no-repeat rgb(249,249,249);

    opacity: .8;

    }

.loader2 {

    position: fixed;

    left: 0px;

    top: 0px;

    width: 100%;

    height: 100%;

    z-index: 9999;

    background: url('../images/ruedas2.gif') 50% 50% no-repeat rgb(0,0,0);

    opacity: .8;
    
        }