var timeIDstopScroll = null; //usado no evento scroll

$(window).scroll(function(){
	if (timeIDstopScroll != null) clearTimeout(timeIDstopScroll);
	timeIDstopScroll = setTimeout(onscrollstop, 50);
});
onscrollstop = function() {
	try{
		$("#alertSite").animate(
			{
				'top': ($(window).height()/3)+$(window).scrollTop()
			}, 
		400);
	}
	catch(e){}
};