#divMain
{
    height: 100%;
    position: absolute;
    width: 100%;
    left: 0px;
    top: 0px;
    z-index: 101;
    background-image: url( '../Dark.png' );
}
#divMainborder
{
    border:10px solid black;
    width:400px;
    margin-left:90%;
    background:#fff;
    position:relative;
    left:15%;
    top:10px;
}