<script src='http://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js' type='text/javascript'/>
<div class='button_up' id='button_up' style='display:none;'/>
<div class='button_down' id='button_down' style='display:none;'/>
<script>
//<![CDATA[
(function(){var special=jQuery.event.special,uid1='D'+(+new Date()),uid2='D'+(+new Date()+1);special.scrollstart={setup:function(){var timer,handler=function(evt){var _self=this,_args=arguments;if(timer){clearTimeout(timer)}else{evt.type='scrollstart';jQuery.event.handle.apply(_self,_args)}timer=setTimeout(function(){timer=null},special.scrollstop.latency)};jQuery(this).bind('scroll',handler).data(uid1,handler)},teardown:function(){jQuery(this).unbind('scroll',jQuery(this).data(uid1))}};special.scrollstop={latency:300,setup:function(){var timer,handler=function(evt){var _self=this,_args=arguments;if(timer){clearTimeout(timer)}timer=setTimeout(function(){timer=null;evt.type='scrollstop';jQuery.event.handle.apply(_self,_args)},special.scrollstop.latency)};jQuery(this).bind('scroll',handler).data(uid2,handler)},teardown:function(){jQuery(this).unbind('scroll',jQuery(this).data(uid2))}}})();
$(function() {
var $elem = $('body');
$('#button_up').fadeIn('slow');
$('#button_down').fadeIn('slow');
$(window).bind('scrollstart', function(){
$('#button_up,#button_down').stop().animate({'opacity':'0.2'});
});
$(window).bind('scrollstop', function(){
$('#button_up,#button_down').stop().animate({'opacity':'1'});
});
$('#button_down').click(
function (e) {
$('html, body').animate({scrollTop: $elem.height()}, 800);
} );
$('#button_up').click(
function (e) {
$('html, body').animate({scrollTop: '0px'}, 800);
} );});
//]]>
</script>
