var name = "#pagetop";
var menuYloc = null;
$(document).ready(function(){
	menuYloc = parseInt($(name).css("top").substring(0,$(name).css("top").indexOf("px")))
	$(window).scroll(function () { 
		offset = menuYloc+$(document).scrollTop()+"px";
		$(name).animate({top:offset},{duration:300,queue:false});
	});
});