减少图片请求，分批加载图片

var lazyLoad = {
	Init: function () {
	return $("img[lazyload]");
	},
	Calculate: function (lazyloadobject) {
	var windowHeight = $(window).height();
	var arrReturn = {};
	var _scrollTop;
	if (lazyloadobject.length == 0) {
	return null;
	}
	else {
	lazyloadobject.each(function (i) {
	_scrollTop = parseInt($(this).offset().top - windowHeight);
	if (!arrReturn.hasOwnProperty(_scrollTop)) {
	arrReturn[_scrollTop] = new Array();
	}
	arrReturn[_scrollTop].push($(this));
	});
	this.ArrLoad = arrReturn;
	return arrReturn;
	}
	},
	ArrLoad: null,
	IsLoad: function (scrolltop, objectstop) {
	if (objectstop != null && objectstop != {}) {
	for (i in this.ArrLoad) {
	if (parseInt(i) <= scrolltop && this.ArrLoad.hasOwnProperty(i)) {
	for (j = 0; j < this.ArrLoad[i].length; j++) {
	this.ArrLoad[i][j].attr("src", this.ArrLoad[i][j].attr("lazyload")).removeAttr("lazyload");
	}
	delete this.ArrLoad[i];
	}
	}
	}
	},
	Run: function () {
	var lazyLoadObject = this.Init();
	this.Calculate(lazyLoadObject);
	arrScrollTop = this.ArrLoad;
	if (arrScrollTop == null) {
	return false;
	}
	else {
	var _this = this;
	_this.IsLoad($(window).scrollTop(), arrScrollTop);
	$(window).scroll(function () {
	_this.IsLoad($(this).scrollTop(), arrScrollTop);
	});
	}
	}
	}
	$(function () {
	lazyLoad.Run();
	});
	$(window).resize(function () {
	lazyLoad.Run();
	});