//autoload.js

 ;! function(e) {

     var autoload = e.autoload || {};

     e.autoload = autoload;

     e.autoload = new function() {

         this.options = {

             id: 'autoload',

         }

         var o = this.options;

         this.include = function(_opt) {

             o = _opt;

             var id = document.getElementById('autoload');

             if(typeof id!=='undefined'){

                 var cssid = id.getAttribute('css');

                 var jsid = id.getAttribute('js');

             }

             cssid = autoload.split(cssid);

             jsid = autoload.split(jsid);

             var c = 0;    //记录js的起始位置

             for(var i = 0; i < o.path.length; i++) {

                 var file = o.path[i];

                 if (file.match(/.*.js$/)){

                     var ind = i+1-c;    //记录js的起始位置

                     if(jsid.toString().indexOf(ind)>-1){ //判断id中的js链接是否存在

                         document.write('<script type="text/javascript" src="' + file + '"></script>');

                     }

                 }else if (file.match(/.*.css$/)){

                     c++;

                     if(cssid.toString().indexOf(i+1)>-1){

                         var Link = document.createElement('link');

                         Link.href = o.path[i];

                         Link.rel = 'stylesheet';

                         document.getElementsByTagName('head')[0].appendChild(Link);

                     }

                 }

             }

         }

     }

     autoload.split = function(str){

         var strs= new Array(); //定义一数组

         strs=str.split(","); //字符分割

         return strs;

     }

 }(window)

 //调用

 autoload.include({

     id: 'autoload'    //引入的该js的id

     //引入的路径

     ,path: [

         'css/a.css'

         ,'css/b.css'

         ,'js/1.js'

         ,'js/2.js'

         ,'js/3.js'

         ,'js/4.js'

         ,'js/5.js'

     ]

 });

</body>前引入，js和css为path中参数的位置，例中js位置为1,2,4从1开始查找，css同理。

 <script src="js/autoload.js" id="autoload" js="1,2,4" css="1,2"></script>