var scrAlpha = 0;
$(document).ready(function(){
$("#totop").click(function(){
$( 'html, body' ).animate({ scrollTop:0},500);
//$( 'html, body' ).animate({scrollTop: $('#footer').offset().top},1000);
})
$("#totop").mouseover(function(){
$("#totop").fadeTo(200,1);
})
$("#totop").mouseout(function(){
$("#totop").fadeTo(200,scrAlpha);
})
$(window).scroll(function(){
var scrTop = $(document).scrollTop(); 
var winHeight = $(window).height(); 
var docHeight = $(document).height();
if(scrTop > winHeight)
{
scrTop = scrTop - winHeight;
docHeight = docHeight - winHeight * 2;
scrAlpha = Math.round((scrTop / docHeight) * 10) / 10; 
}
//$(".qqq").text(scrTop+"+"+winHeight+"+"+scrAlpha);
$("#totop").css("opacity",scrAlpha);
});
$("#sbtn").click(function(){
if($("#shareitem").hide())
{
$("#shareitem").show();
}
else{
$("#shareitem").hide();
}
});
});