百度地图异步加载loadScript()函数

function loadScript() {  
  var script = document.createElement("script");  
  script.src = "http://api.map.baidu.com/api?v=2.0&ak=2337624829697af4d7d4884ea113c174&callback=initialize"; 
  document.body.appendChild(script);  
}  

window.onload = loadScript;