javascript文件加载管理简单实现方法

//按照lightJs的顺序，让网页加载js文件：var lightJs = [  "./js/light/pre/jquery-1.8.0.min.js",  "./js/light/pre/jquery-lib.js",    "./js/light/pre/less-1.4.2.min.js",  "./js/lihgt/pre/util.js",  "./js/xla.js",   "./js/light/light_file.js"];var light;if (!light)  light = {};light.load = (function(lightJs) {  if (!lightJs)    lightJs = [];  var doc = document;  var head = doc.head || doc.getElementsByTagName("head")[0] || doc.documentElement;  for (var i = 0; i < lightJs.length; i++) {    var path = lightJs[i];    var node = doc.createElement("script");    node.charset = "utf-8";    node.src = path;    head.appendChild(node);  }  return doc;}(lightJs));