body 
{    
    /* background: url("../Images/BackSisFullHD.png") no-repeat; */
    -moz-background-size: cover;
    -webkit-background-size: cover;
    -o-background-size: cover;
    background-size: cover;
    clear: both;
    padding-bottom: 35px;
    margin: 0 auto;
    width: 100%;
    height: 100%;
    background-attachment:fixed;
}