.scrollup{
width:40px;
height:40px;
opacity:0.3;
position:fixed;
bottom:10px;
right:30px;
display:none;
text-indent:-9999px;
background: url('../img/icon_top.png') no-repeat;
}

.scrollup_isn{
width:40px;
height:40px;
opacity:0.3;
position:fixed;
bottom:50px;
right:100px;
display:none;
text-indent:-9999px;
background: url('../img/icon_top.png') no-repeat;
}