#rtscrolltop{
height: 40px;
width: 40px;
position:fixed;
bottom:50px;
right:50px;
text-indent:-9999px;
display:none;
z-index: 9999;
background: url("icon_top.png");
-webkit-transition-duration: 0.1s;
-moz-transition-duration: 0.1s;
transition-duration: 0.1s;
}