#scroller{
	position: fixed;    
	right: 20px;
	bottom: 20px;
	z-index: 9999;
	background: transparent url(../images/up.png) no-repeat left top;   
	width: 64px;
	height: 64px;
	cursor: pointer;
	display:none;
	opacity:0.6;
}
#scroller:hover{
opacity: 0.9;
}

.opacity img{
-moz-transition: all 0.4s; 
-webkit-transition: all 0.4s;  
-ms-transition: all 0.4s;  
-o-transition: all 0.4s;  
transition: all 0.4s; 
opacity:1;
filter:alpha(opacity=100);
}

.opacity img:hover {
opacity:0.8;
filter:alpha(opacity=80);
}