.scrollup{
width:51px;
height:51px;
opacity:0.7;
position:fixed;
bottom:30px;
left:50%;
display:none;
text-indent:-9999px;
background: url('../image/ui.totop.png') no-repeat;
}

/*#scrollup {

    background: url(../image/ui.totop.png) no-repeat left -51px;
    width: 51px;
    height: 51px;
    display: block;
    overflow: hidden;
    float: left;
    opacity: 0;
    -moz-opacity: 0;
    filter: alpha(opacity=0);

}*/