css部分loading.css
body{background-color:#e5ffe5}
#loading{width:100%;display:block;position:absolute;z-index:999;text-align:center;}
#loading img{width:100px;height:100px;}js部分loading.js，需配合jQuery使用
$(function(){
$("<link>").attr({rel: "stylesheet",type: "text/css",href:"/js/loading/loading.css"}).appendTo("head");
var loading_height = $(window).height();
var loading_top = parseInt(loading_height/2);
if(loading_top > 100){
loading_top = loading_top-100;
}
$("#loading").html('<img src="\/js\/loading\/loading.gif" style="margin:'+loading_top+'px auto 0px -50px">');
})
$(document).ready(function(){
$('#loading').css('display','none');
$('body').css('background','#fff');
})html部分
<div id="loading"></div>
