sidebar滚动

//sidebar
	$(document).ready(function(){
	var firstTop = 150 + "px";
	$(".sidebar").css("top",firstTop);
	$(window).scroll(function (){
	var offsetTop = $(window).scrollTop() + 150 +"px";
	$(".sidebar").animate({top : offsetTop },{duration:300 , queue:false});
	});
	$('.backtop').click(function(){
	$("body, html").animate({scrollTop:0},300);
	})
	});