body{
    background: url(/style/images/bg.jpg);
}
/* 左上图---右下图 */
.lefttop{ position:absolute; top:0; left:0; z-index:100}
.left_bottom{ left:0px; bottom:80px; z-index:0;position:fixed;}
.right_bottom{ right:0px; bottom:60px; z-index:0;position:fixed; }

.footer_div{width: 1000px;margin: 0 auto;}